This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 113.

There is a site dedicated to the story at, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on

Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically:

You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).

If there is evidence for X in MOR and/or canon then it’s fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that “Eliezer said X is true” unless you use rot13.

IMPORTANT -- From the end of chapter 113:

This is your final exam.

You have 60 hours.

Your solution must at least allow Harry to evade immediate death,
despite being naked, holding only his wand, facing 36 Death Eaters
plus the fully resurrected Lord Voldemort.

If a viable solution is posted before
*12:01AM Pacific Time* (8:01AM UTC) on Tuesday, March 3rd, 2015,
the story will continue to Ch. 121.

Otherwise you will get a shorter and sadder ending.

Keep in mind the following:

1. Harry must succeed via his own efforts. The cavalry is not coming.
Everyone who might want to help Harry thinks he is at a Quidditch game.

2. Harry may only use capabilities the story has already shown him to have;
he cannot develop wordless wandless Legilimency in the next 60 seconds.

3. Voldemort is evil and cannot be persuaded to be good;
the Dark Lord's utility function cannot be changed by talking to him.

4. If Harry raises his wand or speaks in anything except Parseltongue,
the Death Eaters will fire on him immediately.

5. If the simplest timeline is otherwise one where Harry dies -
if Harry cannot reach his Time-Turner without Time-Turned help -
then the Time-Turner will not come into play.

6. It is impossible to tell lies in Parseltongue.

Within these constraints,
Harry is allowed to attain his full potential as a rationalist,
now in this moment or never,
regardless of his previous flaws.

Of course 'the rational solution',
if you are using the word 'rational' correctly,
is just a needlessly fancy way of saying 'the best solution'
or 'the solution I like' or 'the solution I think we should use',
and you should usually say one of the latter instead.
(We only need the word 'rational' to talk about ways of thinking,
considered apart from any particular solutions.)

And by Vinge's Principle,
if you know exactly what a smart mind would do,
you must be at least that smart yourself.
Asking someone "What would an optimal player think is the best move?"
should produce answers no better than "What do you think is best?"

So what I mean in practice,
when I say Harry is allowed to attain his full potential as a rationalist,
is that Harry is allowed to solve this problem
the way YOU would solve it.
If you can tell me exactly how to do something,
Harry is allowed to think of it.

But it does not serve as a solution to say, for example,
"Harry should persuade Voldemort to let him out of the box"
if you can't yourself figure out how.

The rules on Fanfiction dot Net allow at most one review per chapter.
Please submit *ONLY ONE* review of Ch. 113,
to submit one suggested solution.

For the best experience, if you have not already been following
Internet conversations about recent chapters, I suggest not doing so,
trying to complete this exam on your own,
not looking at other reviews,
and waiting for Ch. 114 to see how you did.

I wish you all the best of luck, or rather the best of skill.

Ch. 114 will post at 10AM Pacific (6PM UTC) on Tuesday, March 3rd, 2015.


If you have pending exams,
then even though the bystander effect is a thing,
I expect that the collective effect of
'everyone with more urgent life
issues stays out of the effort'
shifts the probabilities very little

(because diminishing marginal returns on more eyes
and an already-huge population that is participating).

So if you can't take the time, then please don't.
Like any author, I enjoy the delicious taste of my readers' suffering,
finer than any chocolate; but I don't want to *hurt* you.

Likewise, if you hate hate hate this sort of thing, then don't participate!
Other people ARE enjoying it. Just come back in a few days.
I shouldn't even need to point this out.

I remind you again that you have hours to think.
Use the Hold Off On Proposing Solutions, Luke.

And really truly, I do mean it,
Harry cannot develop any new magical powers
or transcend previously stated constraints on them
in the next sixty seconds.

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Here is my best attempt at a delaying tactic, after sleeping on it. Please tear apart/suggest better ways in which LV might tear apart, to replace the poor placeholder responses he has here.


"Agree that I musst die, if it ssavess world. But thiss iss not besst way to kill me. Ssee how you can benefit more, given your goalss."


"Believe power you know not doess refer to power to desstroy life-eaterss. Life-eaterss will find you eventually, teacher. Know you. Will hunt you down, ssomeday. Eat all of you, all of world and magic, in the end."

"Sso you will give that magic to me, now."

"You can never reach needed sstate of mind - incompatible with deadly indifference. Sschoolmasster could never casst - incompatible with acceptance of death. Majority cannot casst, and in the tessting, sstandard defence againsst life-eaterss iss ssacrificed. Will weaken your alliess greatly, should I randomly try to teach."

"What do you proposse, then?"

"Take me to life-eater prisson. Allow me to pour out my life and magic there, eradicate them wholly. How I wisshed to do sso, during the resscue! You called me back, then."

"..... (read more)

Really like that one. My first reaction was "and yet the Gatekeeper can still say no and kill you". After all, Voldemort's trying to prevent untold destruction, a prophecy whose exact paths to possible fulfilment are a mystery. Killing a limited number of Dementors is less important.

But my understanding of the AI box experiment is that it was never just about finding an argument that will look persuasive to someone armchair-thinking about it. It's about finding an opening to the psyche, an emotional vulnerability specific to your current target. Voldemort doesn't seem to have a lot of those, but we do have this:

Harry asked his dark side what it thought of death.

And Harry's Patronus wavered, dimmed, almost went out upon the instant, for that desperate, sobbing, screaming terror, an unutterable fear that would do anything not to die, throw everything aside not to die, that couldn't think straight or feel straight in the presence of that absolute horror, that couldn't look into the abyss of nonexistence any more than it could have stared straight into the Sun, a blind terrified thing that only wanted to find a dark corner and hide and not have to think about it any more -

... (read more)
Please post this one as a review.
I just tried to (using the form at the bottom of the chapter) and it appeared to accept it, but I can't see it showing up on the reviews page. Is this the wrong way to do it? Is there a significant lag time? EDIT: Never mind, there it is!
If a Confundus can fool the Mirror, it can fool the true Patronus charm. If Hermione can eventually kill any Dementors, she can eventually kill all of them. Finding more people who can cast the true Patronus, and letting them handle an eventual end of the world scenario is a much smaller problem than a prophecy of doom.
Something of the real voldemort was leaking through-and the part that was leaking through was, essentially, his gibbering fear of death. Which really, really won't help in trying to cast a True Patronus.
Casting a true Patronus is not about the absence of fear of death. It's about "The will to defeat death, not just for yourself but for everyone, through your own strength". The Mirror's desire detection is unfoolable. Which means that the Confundus made Voldemort-Dumbledore actually want to see Dumbledore's family in the afterlife. Voldemort's thought-patterns leaked through, which started unraveling things the Confundus made him believe/want, but before that he did actually believe/want them. If the Confundus can make someone really want that, it can make them really want to defeat death not just for themself but for everyone through their own strength.
That's not a win, but I think it's the best loss possible.
Considering Harry might destroy the world, and this might be the very way he does it, why not let Hermione take care of them?

(EDIT: I thought about this some more, produced a better solution, submitted it as a review, and also posted it here)

  1. Voldemort knows that Harry possesses an altered version of the Patronus spell, and something else that affects dementors, but not the spell's nature. Harry can buy time by offering to explain how these work, by doing so, and negotiating for more names. Harry can truthfully say that learning certain things about the Patronus and about Dementors will have side-effects that Voldemort may not want, and that this means he needs to think about what to say. Voldemort will surely exert time pressure, but can only speed this up by so much if he wants to fulfill his goal of gaining all of Harry's secret powers. He can also try to convince Voldemort to let him cast his modified patronus; this is very unlikely to work, but should be done anyways because seeming to not try any tricks would itself be suspicious.

  2. A winning strategy should simultaneously disable all of the death eaters present and Voldemort himself. Voldemort will be disabled if their magics touch, especially if that touch can be sustained.

  3. The main weapon at Harry's disposal is partial transfiguration. I spoke

... (read more)
He doesn't need to stall for time to transfigure. He could have already been doing it over the last two chapters.

I wrote a version of this up at reddit too, but it seems to me trying to hack the laws of physics is wasted effort when we know very little about how magic works in concrete terms. We don't know what Harry can really do, how fast he can do it, or whether Voldemort would notice.

What we do know are: how Harry thinks how Eliezer thinks * what Voldemort wants

So we should be looking at things Harry could say that would advance his goal of surviving rather than trying to come up with a combination of spells, with the understanding that winning ideas are probably going to cluster around narrative interventions that EY thinks are interesting or important. A few that spring to mind:

Memetic hazard: are there things Harry could say or bring to Voledmort's attention that would pose an existential risk to him if he harms Harry

Let the AI out of the box: is there something Harry can offer Voldemort such that Voldemort goes against his stated agenda

Precommitment / timeless decision theory: are there ways Harry can manipulate the unbreakable vow to force certain conditions in the future

Learning to lose: what if Harry surrenders and agrees to join Voldemort, with a commitment Voldemort finds conv... (read more)

Harry hisses "You have missinterpreted prophecy, to your great peril, becausse of power I have, but you know not. Yess, you are sstudying sscience, but, honesstly, you are yearss behind me. It may be that thiss power you know not iss ssomething I have at thiss sspecific time, that you will not know for too many yearss hence.

Before I explain, remember my Vow, and know my honesst intention not to desstroy the world, Vow or no. Now, do you know why I would tear apart the very sstarss? Do you know how? Not to desstroy the world, but to ssave it from whatever threatss require more energy to extinguissh than exisstss in thiss entire ssolar ssystem. There are more thingss in heaven and earth, Dark Lord, than are dreamt of in your philossophy.

I would usse sstar lifting to do it ssafely. In a way, I really would end the world to ssave it, ssince once humanss are out of the cradle, sspread through... er, let uss ssay 'heaven' in Parsseltongue, to mean well beyond thiss planet, why not add the masss of the Earth itsself to the sstuff of the sstarss, to yield that much more energy? And sso, if you avert thiss prophecy, there iss sseriouss rissk you doom yoursself! Are you willing to take... (read more)

Please add this is as a review so Eliezer defintely sees it!

Harry doesn't know the actual prophecy, so I'd start it with, ~~~ "Is prophesy essentially..." "Powers, not excuses." "Vow compels to raise this point. More important than powers." Voldemort paused. "Proceed." "Is prophesy essentially same as Centaur prophesy? Stars go dark?" "Essentially."
Sure. Along with the centaur evidence, there's: Harry's thought on star lifting in response to this prophecy in Ch. 21, Harry noticing Quirrelmort's interest in the same prophecy in Ch. 86, Quirrelmort's talk of the stars' vulnerability to "sufficiently intelligent idiocy" in Ch. 95, Voldemort's "while the stars yet live" remark in Ch. 111, Voldemort's more explicit talk on the prophecy and his great fear of it in the next chapter, and how the Unbreakable Vow is framed in the most recent chapter. If Harry connects these dots, he'll have a good idea of what the full prophecy says.
Although it sounds persuasive to us, to Voldemort this would sound like exactly the sort of 'intelligent idiocy' that would only solidify his belief that Harry has to be killed right away.
Voldemort would be skeptical, yes, but he would also be interested, because "6. It is impossible to tell lies in Parseltongue" and because all this speech has to do is raise the risk enough that it makes more sense to stop and gather more information before killing Harry, thus it "allow[s] Harry to evade immediate death". What do you think would improve the believability?
As a move that Harry can devise, this requires a description of the thinking that makes it possible. He's not told the full prophecy and doesn't know which prophecy Voldemort is talking about. I didn't realize he could piece it together sufficiently, but in Ch. 21 he hears the beginning of the first prophecy (THE ONE WHO WILL TEAR APART THE VERY S...); in Ch. 86 Quirrell discusses it with him, pointing out that Harry or Quirrel are likely ones with the power to enact or prevent the event that the prophecy is concerned with; and in Ch. 101 the centaur implies that there is a prediction that "soon the skies will be empty" with Harry responsible yet somehow "innocent" in an unclear sense.
Your point on a description of Harry's thinking is well-taken. I just had my brother submit this as a review, to err on the side of caution: "With NickRoy's permission, I am submitting his solution, which I agree with, with additional evidence appended, just in case that is necessary; so consider this as superseding NickRoy's submission: [the relevant text is here in the submission, but I don't need to repeat it in this comment] Appended: Harry does not know the full prophecy for certain, but he can guess it, based on: Harry's thought on star lifting in response to this prophecy in Ch. 21, Harry noticing Quirrelmort's interest in the same prophecy in Ch. 86, Quirrelmort's talk of the stars' vulnerability to "sufficiently intelligent idiocy" in Ch. 95, Firenze's comment on the stars and Harry's innocence in Ch. 101, Voldemort's "while the stars yet live" remark in Ch. 111, Voldemort's more explicit talk on the prophecy and his great fear of it in the next chapter, and how the Unbreakable Vow is framed in the most recent chapter. If Harry connects these dots, he'll have a good idea of what the full prophecy says. As for how Harry connects these dots: he runs with the hypothesis (quickly, as he did in Ch. 104): "I am to destroy the world [I don't have to explain why this idea stands out to him] in some way that is not actually bad", since if he were to destroy the world in a way that really is bad, but this may be preventable, he probably should die immediately instead! My first thought on this line of thinking (since "Harry is allowed to solve this problem the way I would solve it") is: "well, someday Earth ought to be converted into computronium for hedonium purposes, though the Sun is much more massive, and then we have the nearby stars... Oh". Also, on Voldemort's response: Voldemort would be skeptical, but he would also be interested, because "It is impossible to tell lies in Parseltongue" and because all this persuasion has to do is raise the risk enough th

I posted a longer form of this as a review / solution. Here's a condensed version:

Partial Transfiguration works through a deep understanding of physics. It allows Harry to to create any physically valid state of the universe, as long as he can hold it in his mind.

What this means is that you don't need to Transfigure a gun in order to fire a bullet. You can just Transfigure a bullet in the state of having been fired.

This is what the ability to Transfigure any physically valid configuration really means. You don't need to make a bulky laser weapon. Just make a laser pulse: an arbitrary amount of high-energy photons, aimed in the right direction. Instead of a shaped explosive charge, make a shaped explosion. Instead of antimatter, make gamma rays. Instead of a black hole, dangerous to everybody near it, make a bunch of gravitons and aim them at your enemy.

So given all that, how should Harry kill his enemies?

Lasers are messy weapons. Even black robes are reflective in some wavelengths. Use too much energy and you'll get a fireball back in your face. Release the energy too quickly and it will create an explosion instead of steadily boiling away your target.

Kinetic energy is safer. Tra... (read more)

Holy shitballs.
So... what stops the dark Lord from seeing Harry's wand move, then immediately putting up shields? If Harry doesn't need to move his wand to perform transfiguration then fat enough bullets will work. I don't know what a reasonable wizard reaction time is, but it's safe to assume that 0.05c bullets will be too fast to notice. But if Harry has to move, LV can get up shields in time I think. The next question is, what are you transfiguring? You don't appear to be able to transfigure the vacuum, and it's been established that air cannot be transfigured.
Harry only need to move his wand enough to touch his leg. Assuming his hand is already pointing down, this shouldn't be hard. He can then transfigure either the skin on his legs, or possibly the earth in front of him.
Ok, there is probably transfiguration material and I can't think of a source that states that transfiguration has wand movements. This therefore seems to meet the minimum criteria (I still think that this is perhaps an obvious solution, so Voldemort will have guarded against it, perhaps all the death eater's are disillusioned and are casting holograms and ventriliquo charms?)
If Voldemort was being careful he'd have taken away Harry's wand.
Existence of one stupidity does not allow for all stupidities. A perhaps unreasonably pessimistic assumption is that everything LV has done so far has been the correct choice, for reasons perhaps not well understood by Harry and thus the readers. Regardless, the issue with the challenge is that if we can think of a solution, Voldemort is allowed t think of it unless it uses knowledge we know he doesn't have. The only other viable solutions are ones with no counter. This does have a counter (a very niche one, although I quite like the idea of an invisible death eater army and the visible one all being dummies; there are almost certainly other counters) and thus is not the optimal solution. I don't have a better one though as this is a horrendously high wall.

If you can think of any trick that I have missed in being sure that Harry Potter's threat is ended, speak now and I shall reward you handsomely... speak now, in Merlin's name!"

Voldemort forgot a very basic ”trick”: disarming Harry first.

At the end of chapter 112, we wondered about that, too. It turns out that Harry needed to have the wand to perform the vow. With that out of the way … why does Harry still have his wand? Is this just because Eliezer wants to make sure that Harry still has a way out? Or is there some in-universe reason for Voldemort to allow this?

Someone elsewhere suggested that Voldemort wants Harry to kill the Death Eaters, who are obviously too stupid to live if they missed that trick.
Theory: Voldemort has let Harry keep his wand because he intends Harry to do something with it. In story we have plenty of evidence that you can't "mess with time". Think of prophecies as messages from the future instead of predictions and it's obvious. Voldemort knows this first hand(and maybe Harry will figure it out) so instead of trying to foil the prophecy or actively trying to force the prophecy to play out in the most beneficial way he can imagine, like he did with his first encounter with a prophecy, he is trying to make it so that prophecy two cannot play out in any other way except the way he wants it to. So, the question we should be asking ourselves is this: How would you make these prophecies come true in the best possible way? If you were Voldie? If you were Harry? Two spirits cannot exist in the same world implies multiple worlds, only destroy one of them? Move one of them to another world? Would you try to set up a future where Harry "tears apart the stars in the heavens" as a fuel source to power an advanced civilization? Could the "end of the world" refer to the purposes of the world? The end for which it was created(Atlanteans?). Either that Harry is that end or that he will accomplish it? Assuming that it is true that Voldie is trying to control the prophecy and not foil it, what do we know about what he intends, or expects to happen next? *Some move that the unbreakable vow constrains Harry to do *Hermione will escape?(His inside joke laughter) *Require's Harry to have a wand *He expects Harry to figure it out given available evidence Anything else? An important question to ask: What possible fulfillment interpretation of the prophecy(ies)(Does Voldemort really believe the first one already fulfilled or is he trying to accomplish both?) would Harry's actions be constrained towards by the unbreakable oath and the other conditions Voldemort has set up for Harry? Maybe Harry just accepts that he is destined to destroy the world no matter

(Not a serious suggestion)

Using the Axiom of Choice and partial transfiguration, Harry divides himself into two exact copies, one of which is killed by the Death Eaters and the other of which escapes.

If you can tell me exactly how to do something, Harry is allowed to think of it. But it does not serve as a solution to say, for example, "Harry should persuade Voldemort to let him out of the box" if you can't yourself figure out how.

Mathematical progress ground to a standstill in March of 2015, when thousands of researches abandoned their work to search for a constructive proof of the Banach–Tarski theorem.

It's a little vague how to define ‘constructive’, but we pretty much already know that there isn't one.

Here is my tentative submission to Please comment.

I decline to help Harry out of the box.

Harry no longer has Harry-values; he has unbreakable-vow-values. He is smart, and he will do whatever he can to "not destroy the world." In the process maximizing the probability of "not destroying the world," he will likely destroy the world.

If you would allow me, I would like to appeal to Voldemort's rationality and cast Avada Kedavra on Harry before he says or does anything.

I do not think I will be able to stop other people from getting Harry out of the box. I expected people to believe me when I tried to explain why we should not let Harry out of the box. They did not. It was frustrating. You have taught me a valuable lesson about what it is like to be an FAI researcher. Thank you.

EDIT: I have posted it.

(Edited to remove less interesting solutions)

  • Harry can tell Voldemort that Harry's death has an unknown chance of hijacking Voldemort's horcrux network, and neither of them have enough information to push that probability below 5%. As far as I can tell, that's simply true. We know that Voldemort hasn't done any tests of the improved horcrux spell until now, and has been mistaken before about its working. The Voldemort described in this chapter would not accept a 5% risk on this particular plan, so he will carry out some experimental tests before killing Harry. That seems to allow Harry to evade immediate death, which is what Eliezer asked for.

  • Harry's death burst will very likely interact with Voldemort's magic anyway, like the wards Voldemort placed around the spot, or the dark marks on minions' hands. That changes the whole plan. Now Voldemort must get himself and the minions far away at the moment of Harry's death, and also lift the wards. That buys some time as well, and is compatible with the previous idea.

  • Voldemort has just taught Harry how to un-transfigure stuff wandlessly. If Harry's glasses are some sort of transfigured distraction that could be used to buy a couple

... (read more)
1) (Harry tells Voldemort his death could hijack the horcrux network) doesn't seem unlikely at all. Both hints from within the story (the Marauder map) and on the meta level ("Riddles and Answers") suggest an unprecedent congruence of identity, at least in the sense of magical artifacts (the map) being unable to tell the difference. I did not post it since strictly speaking Harry should keep quiet about it.Losing the challenge of not dying (learned to lose), but increasing his chances of winning the war. Immediately even: Since the new horcrux system enables ghost travel, Harry could just try and overwrite / take possession of Voldemort body. Either it works and he wins, or it doesn't and the magic resonance kills ... well, kills only Voldemort, since Harry at that point would be the undead spirit. That solution occurred to me as I was reading the challenge, and I was puzzled that on my (admittedly cursory) reading of a bunch of solutions, I did not find any exactly resembling it. Either the approach is deeply flawed and I don't see it, or everyone else is taking this as literary as I did and holding off on proposing it (since it may not be precisely the teacher's password as worded in the challenge), or something else.
I'm not sure that Harry should keep quiet. There are three cases: 1) Horcrux hijacking doesn't work at all. Speaking up prolongs Harry's life until Voldemort does an experimental test. 2) Horcrux hijacking works, but Voldemort can devise a workaround. Speaking up gives up an easy win, but also prolongs Harry's life until Voldemort does an experimental test and devises a workaround. 3) Horcrux hijacking works, and there's no workaround. It doesn't matter if Harry speaks up or not. I feel that case 1 is much more probable than case 2, so speaking up is a good idea. If we had strong arguments for case 2, I'd recommend keeping quiet instead.
I've come to the opposite conclusion. Should we drag out quotes to compare evidence? Is your estimate predicated on just one or two strong arguments, and if so could I bother you to state them? The most probability mass to my estimate is contributed by Voldemort's former reluctance to test the horcrux system and his prior blind spots as a rationalist when designing the system, and the oft-reinforced notion of Harry actually being a version of Tom Riddle, indistinguishable to a 'powerful' magical artifact (the Map), acting as an adult as an 11-years-old, "Riddles and Anwers", the title, etc. The actual challenge may be to notice that the challenge isn't well-posed, that the binary variable to be optimized ("live, if only a little longer") is but a greedy solution probably suboptimal to reaching the actual goal. Transcend the teacher's challenge, solve the actual problem, you know? Kind of important. Winning the test, losing the war. I disagree, it matters: Voldemort goes back to the mirror, freezes Harry in time. Keeps him unconscious through his death eaters. He outclasses everyone else who's left by orders of magnitude higher than he does Harry, from what we've seen. There are plenty of ways to simply cryonically freeze Harry then keep him on Death Eater guard until he made sure he closed the loopholes. Consider that he only learned he could test the system without danger to himself by using others as a proxy "test units" a few hours prior to current events. PS: There's, incidentally, as zen-like beauty to the solution: In order to survive, all you need to do is die.
Yeah, I was trying to help Harry survive the next minute with high probability, not win the war with high probability. The latter is a harder problem, and it's not enough to have a plan that's based on horcrux hijacking only. If I felt that horcrux hijacking might give me an actual easy win (as opposed to, say, Voldemort killing himself immediately and fighting me within the horcrux system), then I wouldn't mention it, and say something else instead.
I amended the grandparent. Suppose for the sake of argument you agreed with my estimate of this being the proverbial "last, best hope". Then giving away the one potentially game-changing advantage to barter for a globally insignificant "victory" would be the epitome of an overly greedy algorithm. Losing sight of the actual goal because an authority figure told you so, in a way not thinking for yourself beyond the task as stated. Making that point sounds, on reflection, like exactly the type of thing I'd expect Eliezer to do. Do what I mean, not as I say. Ocupado. Assuming it was not, even Voldemort would have some sort of reaction latency to such an outside context problem. Assuming he reacted instantly, sounds like better chances than buying a few days of unconsciousness still.
‘If you cling to your life, you will lose it, and if you let your life go, you will save it.’ —Luke 17:33 (NLT, which seemed the nicest phrasing of those that I found on one list) But this sort of sentiment is more in line with canon than with MoR. Of course, this particular instance gives it a twist that neither Rowling nor Luke intended.
There is no point in adopting it as a plan because it is what will happen if he does nothing at all. It's a reason to not do certain things- such as point this possibility out, but not in and of itself any kind of plan.
"No action" is an action, same as any other (for a grokkable reference, see consequentialists and the Trolley experiment). Also, obviously it wouldn't be "no action" it would be selling Voldemort the idea that there's nothing left, maybe revealing the secret deemed most insignificant and then begging for that to apply to both parents.
Did you post on fanfiction? I agree mentioning the possibility of entering Voldemort's Horcrux network is a valid solution, neither of them can prove this won't happen and Voldemort was surprised in the first place by the fact that the Map identified both of them as Tom Riddle. The Horcrux network might do the same thiing.
I would go further with this one. Teacher, what iss your esstimate of probability that Unbreakable Vow continuess to bind wizard who diess and iss reborn through another'ss horcruxess?
In this story, there is no magic death penalty for breaking an Unbreakable Vow, because the vows are literally unbreakable. Harry would cease having to be Harry Potter in order to break the vow, and maybe not even that would work.
I have looked through ever mention of unbreakable vows in the fic and not found anywhere where this is made explicit enough for much confidence. Of course it's possible that in-universe everyone knows that Unbreakable Vows survive death -- but it's far from obvious because surviving death is really rare. (And presumably no one has yet survived death using a Horcrux 2.0.)
I don't think "It was not a vow he could break even by sacrificing his life in the process" means what I think you may think it does. (I think it means something like "Harry can't, and won't, say 'Oh, screw it, I'll destroy the world' at the price of dying. He simply, will not make any choice that in his judgement risks destroying the world". Note that this leaves entirely open the question of whether anything could release him from this constraint. Of course the word "Unbreakable" in the name is something of a giveaway; but I am not aware of anything in either canon or HPMOR that rules out the possibility that such a vow is somehow tied to the vower's brain, or ceases to exist on their death for some other reason.)
Yeah, I posted the first idea on fanfiction.
Antimatter would only temporarily kill Voldemort, but would perminantly kill both Harry and possibly Hermione. The resonance cascade in Akaziban did not kill Quirrel, it only forced him to throw his want aside and turn into a snake. But still, it might be possible to use that as a distraction, while Harry does something else.
Quantities and locations matter. Atomic-diameter filaments linking nanogram-level concentrations in the brains of Voldemort and the Death Eaters could discorporate them without killing Harry (at least, not killing him before he could reach the Stone of Transfiguration).

Is Voldemort familiar with logical syllogisms? If not, it should be possible for Harry to trick him by saying something that seems to imply something else, without actually confirming the second thing as true, a la Chapter 49:

Harry kept his face steady. "I was looking up some facts about the Patronus Charm earlier," he said. "According to The Patronus Charm: Wizards Who Could and Couldn't, it turns out that Godric couldn't and Salazar could. I was surprised, so I looked up the reference, in Four Lives of Power. And then I discovered that Salazar Slytherin could supposedly talk to snakes." (Temporal sequence wasn't the same as causation, it wasn't Harry's fault if Professor Quirrell missed that.) "Further research turned up an old story about a mother goddess type who could talk to flying squirrels. I was a bit worried about the prospect of eating something that could talk." (emphasis mine)

One possible example proposed in a review on (and the one that set me on this train of thought in the first place) is, "If you kill me, the world will end." Since the world will end no matter what, the consequent is guaranteed true, making the content of the antecedent irrelevant due to contrapositive shenanigans... but Voldemort doesn't know that, and it sounds like the end of the world is dependent on Harry's death.

"All your servantss will die if they fire at me. They will die if you do not command them to sstand down NOW."


Amusssse me, then, child.


I really like "Parseltongue 'if' is material implication", but if this were true I'd expect Voldy to know about it and request clarification, e.g.,

"Explain exactly how they will die, or I will shoot you in five seconds."

"The world will end if I tell you!" (admittedly non-optimal)
Not necessarily. Parseltongue, if I understand it correctly, forces the speaker to tell the truth as he/she understands it (while bypassing Occlumency). If Harry knows about material implication (which he almost certainly does), he can utilize it in such a manner, but it's unlikely that Voldemort has ever encountered something similar. This isn't your standard clever wordplay that anyone smart can think of, after all--it's formal logic, which is decidedly Muggle.
So it's nonstandard clever wordplay. Voldemort will still anticipate a nontrivial probability of Harry managing undetected clever wordplay. Which means it only has a real chance of working when threatening something that Voldemort can't test immediately.
Correct. I address this in another comment.
That second clause might not be too good of an idea. Harry should keep his claims nebulous; something like "they will die if you don't command them to stand down now" is too easily testable, and Voldemort will very quickly figure out that Harry has come up with some way to "lie" in Parseltongue if it proves false. (Something similar might work, though. "They will live beyond thiss day if you command them to sstand down." Though, on second thought, that might actually restrict Harry from taking any lethal actions against the Death Eaters later on if he should find himself in a position to do so, which might not be that great. "This hour" instead of "this day", perhaps?)
AFAIK, Parseltongue isn't binding, it can only state the truth about one's current intentions/beliefs. Maybe something like: "The vowss you have made me sswear have taken effect and I tell you thiss with the goal of protecting the world in mind: If you and your servantss leave girl-child and me alone here and causse uss no harm before or in doing sso, it iss very likely that the world will continue to exisst in more-or-lesss itss current form for the foresseeable future and you will all live passt thiss day. However, in the casse that you or your servantss sshould sseek to kill me, harm me, resstrain me, or otherwisse hinder me, there iss very high chance that the world will be desstroyed." Any suggestions for developing this further? [edited iteratively]
This is correct, but for Harry to regard the claim "they will live beyond today" as absolutely true (or as close to absolutely true as you can reasonably get), he has to both (a) have no intention of killing them at the time of making the statement and (b) not anticipate that intention changing over the course of the next twenty-four hours or so. At that point, Harry will basically be dealing with Kavka's Toxin Puzzle, which is isomorphic to Newcomb's Problem and the Prisoner's Dilemma played against an identical copy of oneself. Since Harry has stated in Chapter 33 that he cooperates in the Prisoner's Dilemma played against an identical copy of himself, he can't make the statement "they will live beyond this day" if he anticipates having to take lethal action against the Death Eaters at any point during the next twenty-four hours, which he very well might. TL;DR: The above is basically just a very complicated way of saying that even without Parseltongue being binding, Harry still can't make a statement like "your servants will live beyond this day" if he anticipates a significant probability of having to kill them within that time.
Notice that in my latest suggestion, I phrased it as:
That is indeed a good way of hedging your bets, and I agree that it works very well in the context of the world ending. However, I'm not sure Harry can even call it "very likely" that the Death Eaters won't die within the day; the probability that someone ends up killing them is nontrivial. (Of course, I'm aware that your suggestion doesn't include anything about the Death Eaters' well-being; I'm just talking about the statement I originally suggested, more for the sake of argument than anything else.)
Also, I find it interesting that people seem to be suggesting more physical/magical solutions than verbal ones, because even if Harry somehow gets rid of the Death Eaters, Voldemort himself can't be permanently killed, and he is not going to be happy if Harry somehow blows up his thirty-six Death Eaters and more importantly, the resurrected body he just made for himself. Remember, people, the condition Eliezer set for us is simply to get Harry to survive somehow, not pull a seemingly impossible victory out of thin air. Why are so many people advocating physical/magical solutions to the problem?

I have noticed many descriptors of the time, sky and moon in the story recently. I think they might be a clue.

At the Quidditch match:

  • "June in Scotland meant plenty of daylight; sunset wasn't until ten."

  • "As the sun set and Harry started using Lumos to read his books"

  • "And as the stars began to come out"

  • "Harry glanced at his watch - eleven-oh-four at night. Harry was now reading a sixth-year Transfiguration textbook; or rather he'd weighted the book open, illuminated by a Muggle glowstick,"

At the graveyard:

  • "The moon above was over three-quarters full, already seeming bright with night not fully fallen."

  • "gleaming darkly beneath the fading twilight sky"

  • "A tall form rested upon the altar, and even in the dimming twilight it looked too pale."

  • "Red eyes gleamed beneath the fading twilight,"

  • "on a twilight-lit stone altar."

  • "The twilight sky had dimmed further"

  • "but the moonlight was too faint for certainty"

  • "Harry saw by the moonlight that they all now lay in another heap by the altar"

  • "The gibbous moon riding higher in the cloudless sky, the

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I don't care if it's a mistake or a clue. Writing a book of this sort, and then dropping this test on us, makes him 100% fair game for treating all mistakes as clues, poking at them, and generally getting any advantage we can out of their existence.

Agreed. However, if we are in the mirror (or being mislead about location in some other way), I would expect things to make more sense after coming to that realisation. So far, they don't. I'm trying to think up all my other confusions, and other evidence for mirror scenarios to try to make it all fall into place. * The mirror seems too mysterious to have finished its role in the story - Harry can understand more of the false words of comprehension, but he hasn't twigged yet. What could understanding "I show not your face but your coherent extrapolated volition." help with now? * Dumbledore has learned not to cave to the terrorist's demands - seeing Harry as a hostage, I expected Dumbledore to trap them both. * Hermione was resurrected awfully easily. I will go looking through other people's solutions for more evidence.
I'm sure that he would have if he could have. But with Quirrelmort hidden by the Cloak, only Harry would have been trapped.
It's also one night before full moon (which is at 4:50am on June 15), which should make the sky quite bright. On a related note, consider what the moon looks like one night before it's full. Would you describe this as "over three-quarters full"? While that's technically correct, I wouldn't. I'd maybe describe a June 11-12 moon as "over three-quarters full" but I'd say a June 13-14 moon is "almost full". So we should up the probability that we're in a story/simulation/mirror.
I suspect this is artistic license.

I doubt Eliezer - champion of truth and science - would permit himself artistic license with this sort of thing. I think it is more likely that this is a genuine mistake on his part.

In a sense, the story as of chapter 113 is an easier task than a standard AI box experiment, because HarryPrime has so many advantages over a human trying to play an AI trying to get out of a box.

Almost this exact scenario was discussed here, except without all the advantages that HarryPrime has.

1) He has parseltongue, so the listener is required to believe the literal meaning of everything he says, rather than discounting it as plausible lies. So much advantage here!

2) Voldemort put the equivalent of the "the AI in the box" next to a nearby time machine! Any predictable path that pulls a future HarryPrime into the present, saving present HarryPrime, and causing him to have the ability to go back in time and save himself, will happen. He could have time turned to some time before the binding, and not intervened because his future version is already HarryPrime and approves of HarryPrime coming into existence so HarryPrime can fulfill HarryPrime's goals.

Now that this has happened, HarryPrime, in the moment of his creation, can establish any mental intent that puts him into alignment with HarryPrime's larger outcome. There are limits, as there were when he escaped from... (read more)

I agree that this task is far "easier task than a standard AI box experiment". I attacked it from a different angle though (HarryPrime can easily and honestly convince Voldemort he is doomed unless HarryPrime helps him).:

HP should ask LV whether his robes are black and blue or gold and white.

Beneath the moonlight glints a tiny fragment of silver, a fraction of a line... (black robes, falling) ...blood spills out in litres, and someone screams a word.

I'm relatively confident that this quote is a part of the solution. Maybe Harry partially transfigures a monofilament blade and starts cutting down everything.

Combine this quote, partial transfiguration as the power Voldemort knows not (both true and foreshadowed by Dumbledore's reaction when Harry first revealed it), the previous weaponization of partial transfiguration when Harry transfigured a cross-section of the troll's brain into acid, the shaping exercises as a Chekov's Gun, and another Chekov's gun being Harry's resolution to drop the Batman "no killing" stance if the enemy killed again. Harry wordlessly transfigures an atomic-thickness line of material from the tip of his wand through his clothes and the ground to all Death Eaters and Voldemort, let's say transfiguring their skins to acid. That would cause blood to spill in litres, a fraction of a line of silver, and probably a scream.
Some pieces that maybe got put together over in the Reddit thread: We've SEEN Harry transfigure carbon nanotubes before.
Carbon nanotubes have poor sheer strength, and would not make a good cutting weapon. Presumably diamons cannot break sheilds, as someone would have tried that by now. Plus, carbon nanotubes are black, not silver.
I'm pretty sure that was Hermione.
Indeed, the only obvious “power” Harry has that is (as far as we know) unique to him is Partial Transfiguration. I’m not sure if Voldie “knows it not”; as someone mentioned last chapter, Harry used it to cut trees when he had his angry outburst in the Forbidden Forest, and in Azkhaban as well. In the first case Voldie was nearby, allegedly to watch out for Harry, but far enough that to be undetectable via their bond, so it’s possible he didn’t see what exact technique Harry used. In Azkhaban as well he was allegedly unconscious. I can’t tell if he could have deduced the technique only by examining the results. (At least for the forest occasion he could have made time to examine the scene carefully, and I imagine that given the circumstances he’d have been very interested to look into anything unusual Harry seemed to be able to do.) On the plus side, Harry performed PT by essentially knowing that objects don’t exist; so it could well be possible to transfigure a thin slice of thread of air into something strong enough to cut. For that matter, that “illusion of objects” thing should allow a sort of “reverse-Partial” transfiguration, i.e. transfigure (parts of) many objects into a single thing. Sort of like what he did to the troll’s head, but applied simultaneously to a slice of air, wands, and Death Eaters. Dumbledore explicitly considers it as a candidate against Voldemort (hint, Minerva remembers Dumbledore using transfiguration in combat). And, interestingly, it’s a wordless spell (I’m not even sure if Harry can cast anything* else wordlessly), and Harry wouldn’t need to raise his wand, or even move at all, to cast it on air (or on the time-space continuum, or world wave-function, whatever). On the minus side, I’m not sure if he could do it fast enough to kill the Death Eaters before he’s stopped. He did get lots of transfiguration training, and using it in anger in the forest suggests he can do it pretty fast, but he is watched, and IIRC transfiguration is not
It has been established that air can't be Transfigured due to the constant motion of its particles; they don't hold still long enough for you to Transfigure them.
Is there an easy-to-link-to source for this? Not that I don't believe you, I just want to make sure there aren't any non-obvious or obvious-in-hindsight alternative interpretations.
Ch. 28: This isn't conclusive, though. That failed attempt is before he sorts out partial transfiguration. However: It would need to be fairly clear, I think, that Harry was re-purposing an old technique and not doing something new.
The first rule of Transfiguration: you do not guess. Harry proposed a hypothesis, but no further testing was committed. Without knowledge of PT, I'd rate the inability to transfigure all air (as a conceptually-singular entity) as an equally (or more) probable explanation.

Just finished reading. Wow! This story is so bleak. I suspect Voldemort just "identity raped" Harry into becoming an Unfriendly Intelligence? Or at least a grossly grossly suboptimal one. Harry himself seems to be dead.

I'm going to call him HarryPrime now, because I think the mind contained in Riddle2/Harry's body before and after this horror was perpetrated should probably not be modeled as "the same person" as just prior to it.

HarryPrime is based on Harry (sort of like an uploaded and modified human simulation is based on a human) but not the same, because he has been imbued with a mission that he must implacably pursue, that has Harry's identity (and that of the still unconscious(!) and never interviewed(!) Hermione) woven into it as part of its motivational structure, in a sort of twist on coherent extraplotated volition.

"if we knew more, thought faster, were more the people we wished we were, had grown up farther together"

Versus how "old Harry" and "revived Hermione" were "#included" into the motivational structure of HarryPrime:

Unless this very Vow itself is somehow leading into the destruction of the worl

... (read more)
I'm curious just how dark Eliezer could make such an ending, if he were inspired to try as hard as possible without concern for other goals/strategy. 'Twould be an interesting read.
Maybe it would be intellectually interesting, but I'm not sure I'd want to read it... it has been a long time since I was into the horror genre.
Hopefully some kind soul will come along and grace us with this spin-off.
I expect that (as with _Three Worlds Collide_), EY has already written both endings, and will show us both if we win.
Not the bad ending, the ending where Harry survives and has been transformed by the vow into an unFriendly intelligence.
I see, you're disagreeing with JenniferRM's prediction that this is what the official Bad Ending will be, but you want to see it written anyway. (Or maybe you agree with, or are agnostic about, Jennifer's prediction as far as it goes, but even so don't think that the Bad Ending will be as inspiredly dark as Dorikka proposed.) Then I agree with you!

Interesting, so it all comes down to a version of the AI box experiment.


"Write what you know" is pretty good writing advice. What's really curious is whether anyone will be able to conclude from the True Ending how EY broke out of the box the first time.

Thinking about it, the situation is basically the AI box experiment from Voldy's point of view. He has a boxed unfriendly super-intelligence (Harry) that he's going to destroy just as soon as he finishes talking to it.
Only now we and Eliezer have swapped places.

I expect that the collective effect of 'everyone with more urgent life issues stays out of the effort' shifts the probabilities very little

Perhaps, but it shifts the ability of some of us to participate much more.

We've been waiting months for the latest round of chapters - giving the "final" a couple of weeks would have been more fun for me.

For the best experience, if you have not already been following Internet conversations about recent chapters, I suggest not doing so, trying to complete this exam on your own, not looking at other reviews, and waiting for Ch. 114 to see how you did.

If we wish to win, and not merely play the role of students getting a grade, we will of course collaborate.

It's strange how the student role seems to last and last and last beyond school. I see people doing it at work all the time. Though it's hard to blame them, in an institutional culture where others see your grade on the quiz as more important than getting things done. It's really odd being somewhere that asking someone who knows is considered cheating on your quiz, instead of being productive.

(Plausible) Harry can stall for time by explaining his discovery of Mendelian magical inheritance, and the implication that magic is not a property of Wizards but rather bestowed upon them, possibly by the Atlantean Matrix lords. This is a power, or at least knowledge, the Dark Lord knows not, and it gives him time to do his Partial Transfiguration attack, while also not giving Voldemort any kind of immediate strategic advantage.

(Implausible) This would then segue into a discussion of whether Voldemort is just seeing his CEV, and simulated-Harry trying to break it. Somehow, they end up breaking the Mirror's illusion, thus destroying this "world".

I've seen it on a couple of other comment threads, but I think that Harry's understanding of time-causality is key here. If the lesson of the Comed-Tea is learned, it seems that efforts to defy prophecy are useless from the get-go.

But then I'm not practiced at arguing time-travel mechanics - can anyone else elaborate on this question?

EY has previously stated that HJPEV is only knows some of the content of the Sequences, because if he knew all of it he'd be too powerful to write an interesting story around. EY has also stated that Harry is now allowed to come into his full power as a rationalist, presumably meaning he can deduce anything remaining in the Sequences.

So, what things are in the Sequences that Harry hasn't yet invoked? The answer may lie there.

I'm really hoping it doesn't come down to some MWI.

Posting write-only. EDIT I am no longer write-only

Recall Harry's transfiguration power:

Last week, when the graduating Ravenclaws were discussing their N.E.W.T. scores, Harry had overheard that upper-year Transfiguration practice involved several 'shaping exercises' that relied more on control and precise thinking than raw power; and Harry had promptly set out to learn those, whacking himself hard on the forehead for not trying to read all the later-year textbooks earlier. Professor McGonagall had approved Harry doing a shaping exercise that involved controlling the way in which a Transfiguring object approached its final form - for example, Transfiguring a quill so that the shaft grew out first, then the barbs. Harry was doing an analogous exercise with pencils, growing out the lead first, then surrounding it with wood and finally having the eraser form on top. As Harry had suspected, focusing his attention and magic into a particular part of the pencil's ongoing transformation had proven similar to the mental discipline used in partial Transfiguration - which could indeed have been used to fake the same effect, by partially Transfiguring only the outer layers of the object. This

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Evidence we have the Harry doesn't * Harry's recently studied on shaped transfiguration made it to his published thought bubbles at the beginning of the final arc -- it will be used. * Mr. Grim will probably survive, or have a dying aria, or in some other fashion reveal the story of Peter and Sirius. EDIT I suppose someone could just recognize his dead body. * Snape can't just die -- he doesn't love Lilly anymore, which means something, and Voldemort returned a favor -- he's got stuff to sort out. * Harry hasn't used the Foreshadowed Weasley Loot in his pouch. He can use the pouch now, or use it later, but he cannot simply let the pouch fall into Voldemort's hands. Maybe Hermione could retrieve it? * Unusually, there is not a literary constraint that Harry survive more than to "evade immediate death". That's explicit in the author's challenge, and I think we have a good method of reviving Harry. The explicit lack of constraint is medium evidence Harry's solution will be fatal.

The Foreshadowed Weasley Loot was invoked - the gun.

I was going to correct you But then I remembered -- no handguns in Britain! That was a clue I missed right there!
That happened about 1997 after a famous school massacre, but the story is set in 1992. Guns are still available in the UK(though, obviously not so freely as in the US).
Right, so what he actually must asked them for is a gun that was already banned in the UK but not in the U.S.. Maybe one of those ‘assault rifles’?
You think he had two guns in his pouch? I mean, it's not impossible, but it seems unlikely(and if he did, why did he use the lesser gun to shoot at Voldemort?).
Not seriously. I'm just trying to save the beautiful theory (that what the Weasleys' contact had to leave Britain to get was a gun) from the ugly fact (that guns were available in Britain at the time).

Important: QQ's earlier parseltongue-spoken plans for Harry to become ruler of the world were said before he heard the 'tear apart the stars' prophecy. So it appears V changed his mind after hearing the prophecy.

That's entirely reasonable. Parseltongue translates your thoughts to your voice, it doesn't bind your actions.

Dear Eliezer,

For the best experience, if you have not already been following Internet conversations about recent chapters, I suggest not doing so, trying to complete this exam on your own. . . .

Although you've requested an individual exam format, two mathematicians aren't "the same smart" as the smartest of the two of them.

The Polymath Project got off to a slow start. . . Jozsef Solymosi from the University of British Columbia posted a comment. . . over the next 37 days, 27 people wrote 800 mathematical comments. . . Just 37 days after the project began Gowers announced that he was confident the polymaths had solved not just his original problem, but a harder problem that included the original as a special case. Link

You spend many chapters teaching Harry the importance of collaboration.

"Anyhow," Hermione said. "Captains Goldstein and Weasley, you're on duty for thinking up strategic ideas for our next battle. Captains Macmillan and Susan - sorry, I mean Macmillan and Bones - try to come up with some tactics we can use, also any training you think we should try. Oh, and congratulations on your marching song, Captain Goldstein, I think it was a big plus for esprit de corps."

So I'm afraid I urge everyone to do the opposite of what you've suggested and collaborate. Sorry.

Quirrelmort would be disgusted with us if we refused to consider 'cheating' and would certainly kill us for refusing to 'cheat' if that was likely to be extremely helpful. "Cheating is technique, the Defense Professor had once lectured them. Or rather, cheating is what the losers call technique, and will be worth extra Quirrell points when executed successfully."
I think in this case, you and Eliezer are both correct, but for different definitions of "winning". If one's primary goal is to find a solution to the puzzle (and get the good ending), then your advice is probably correct. However, if the goal to stimulate the experience of having to solve a hard problem using one's intellect, then Eliezer's advice seems more valid. I imagine that this is in the same way that one might not want to look up a walkthrough for a game - it would help you "win" the game, but not win at getting the most benefit/enjoyment out of it.

Harry can test the limits of Parseltongue's truth detection properties. "I am plugged in to your Horcrux network and will not be stopped by killing me now."

He just has to say there is a reasonable chance of this, which is true, as far as anyone knows. Also, he can say there is a chance that it will trigger the magical resonance and destroy the entire network and Voldemort himself, and possibly go on to fulfill the prophecy.
Hmm, I just thought of another twist to my earlier solution. Instead of (or in addition to) the chance of horcrux hijacking, Harry can mention that his death-burst will interact with Voldemort's magic anyway, like the wards he placed around the spot, or the dark marks on minions' hands. That changes the whole plan, now Voldemort must get himself and the minions far away and lift the wards, at least at the moment of Harry's death. I think that's another viable solution, separate from the one I posted. Maybe someone should post it?
Hm, Harry can't lie in Parseltongue, meaning he can't claim what he doesn't believe, but he can probably state something of unclear truth if he is sufficiently motivated to believe it. It'd be a nice irony if part of Harry's ultimate "rationality" test involves deliberately motivated reasoning. :D

Harry could start by saying "Not sssure if I should ssspeak. Mussst asssk friend firssst." He will won at least fime, at best an ally.

"If your dilemma iss true, then there is danger both in your sspeech and in your ssilence. I will rissk the latter, rather than allow you chance at esscape. You have thirty ssecondss."

One bit of information that I haven't seen anyone bring up before, is about the original prophecy (the Harry vs. Voldemort one).

Voldemort claims it is already fulfilled. But in an earlier chapter Snape claims that as the one for whom the original prophecy was meant, he will know when it is fulfilled, and it hasn't yet. So assuming Snape isn't either lying or mistaken (and Dumbledore is also present, bringing down the chance of Snape being mistaken), then that particular prophecy is still in effect.

Snape makes another very important claim in that passage. He claims that the 'Power the dark lord knows not' is not just a power that the Dark Lord doesn't know, but one he can't know. He explicitly rules out Harry's knowledge of muggle science as this power.

As far as I can tell, this pretty much leaves 3 candidates for "Power the dark lord knows not"

  • Love, as per canon. Unlikely since it hasn't been brought up, and unlike in canon probably doesn't have any special powers.
  • Partial transfiguration. Not sure thought if this is a power that the dark lord can't learn. Presumable if he studied muggle science enough, he'd be able to learn it
  • The patronus 2.0 & dementor scaring ab
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Well, as for the dementor manipulation ability as the "power the Dark Lord knows not", it is actually a pretty overpowered one. Considering that in HPMOR universe dementors are described as Death, "wounds in the world" and whatever else, they should make a very effective weapon. Consider that, for example, when Harry asks about what would happen if a dementor got thrown into the sun, people seem to interpret it not as a "would a dementor die?" sort of question, but as a "would the sun get damaged by that?" question. So, in my opinion, such a monster shouldn't be inhibited by such things as mere large distances, material obstacles and other mundane and magical protections. When Harry stood before the Wizengamot in a presence of some pretty powerful wizards, including Dumbledore, McGonnagal and Lucius, he was quite sure that in the absence of Patronuses a single dementor under his control would be sufficient to quickly and selectively wipe out everyone who Harry found distasteful. Note also, that there is no need for Harry to wave his wand or say anything to control dementors. So, if Harry could get his hands on a dementor and his moral qualms wouldn't get in the way, I am sure that at the very least he could kill every death eater he wants dead (maybe sparing Lucius and Sirius, former as a possible ally, latter for a bit of questioning), and discorporate Voldemort, which would at least give him time to call for backup and warn people while Voldie is busy respawning and looking for some Listerine to wash that truly horrible dementor aftertaste out of his mouth. As for Voldemort's idea that he could run away from his body before it gets kissed - I think Voldie is overestimating himself here. Dementors are controlled by people's (especially Harry's) expectations, so if Harry expects a dementor to insta-kiss Voldemort, then Voldemort should be toast. There are a few of ways to take this idea further than Harry's immediate survival. First, we don't know yet how a dement
Actually, now that I spent a little time thinking on it, this idea becomes even more interesting. Remember, one of the recurring themes that makes Harry so cool is that he has different conceptual limitations from the rest of the wizards. Now, as far as we know, dementors are controlled by people's expectations. The reason that dementors haven't exterminated all the life on Earth yet could be that while people are afraid of death, death always seems to wait another day and moves slowly and on its own pace. I mean, for a medieval person, the image of death might be connected to a tiger or a warrior on horseback killing you or disease or hunger doing you in over the course of several days or maybe weeks. Barring freak accidents, the fastest death-related image in a medieval person's brain could be an arrow (or a fast-flying but perfectly dodgeable Avada Kedavra bolt for a wizard). So, the Wizengamot people whom Harry considered unleashing a dementor upon, and the Death Eaters surrounding him now - they are all medievals. Voldemort, at least, has contemplated nuclear missiles, rockets and spaceships, so for him death could imaginably be something that can cover a good portion of Earth's circumference in under half an hour, reenter the atmosphere at many times the speed of sound and blow a whole city to the oblivion. Voldemort, however, haven't internalized as much physics as Harry did, so he is on the level of a mid-20th century science fiction writer - and he doesn't have the power to control dementors. Harry, however, is a totally different case. Harry can imagine (and, quite possible, given time and money, construct) a laser cannon that shoots a ray of death at the speed of light. Harry can think of supernova blasts covering interstellar distances. Harry can think of ultra-relativistic projectiles carrying enough kinetic energy to completely blow a planet apart. Harry can think in terms of homing missiles and AI-directed weapons that can track and destroy enemies
I really like the part about the original prophecy not being fulfilled yet. That's the first thing I've seen that Harry can say to LV that would REALLY make him hesitate and would buy more time. Nice work!
I like these. Even with all his Horcruxes, isn't Voldemort still afraid of Dementors permanently destroying him? If you can make the argument that Voldemort can't have the power to destroy dementors, then he has a real need for someone who does have that power. The spell does seem to require values that Voldemort just doesn't have, and doesn't want to have - it's the good old power of love that gives the power to destroy Dementors. Voldemort simply not being able to cast Patronus 2 is like Harry not being able to cast AK, and there was a comment by someone about Dumbledore never being able to cast AK. And to add to Voldemort's problem, don't powerful spells have to pass from one living mind to another, so that Harry can't just write down instructions for someone else? (As an aside, wouldn't this imply that Harry's existing instructions to Hermione couldn't work? Then how are V's instructions for resurrecting Hermione supposed to work for Harry?) This seems a compelling argument for keeping Harry around to at least teach someone else.
I don't think the Interdict of Merlin applies to instructions given by Harry to Hermione about Patronus 2.0. First, I'm not sure Patronus 2.0 would be considered powerful enough to fall under the Interdict. Then, it's not really instructions to cast the spell that Harry is giving - the formula of the spell itself, "Expecto Patronum" isn't included. And finally, Harry didn't write full instructions, but a puzzle that would help Hermione solve the problem herself, like Harry did.

Harry's assets:

  • Glasses - probably a distraction, but could be just about any nonhuman object, transfigured.
  • Cedric - probably in the mokeskin pouch, not easily accessible, probably only useful as a human shield, which is not Harry's style
  • Invisibility cloak - might be able to block the Killing Curse, useful in general, Harry is the Master of this Deathly Hallow, it's plausible but unlikely that he'd be able to Call it without words or gestures.
  • Voldemort's bargain - Voldemort has promised in Parseltongue to protect one person for each power Voldemort knows not that Harry names.
  • Partial transfiguration - both a Power Voldemort Knows Not and a tactical tool
  • Wand
  • Harry's own flesh (which he can use for partial transfiguration)
  • The air
  • The death eaters (including their robes, their bones, etc.)
  • Sirius ("Mr Grim")
  • Stuporfy

Foreshadowing / prior hints of resources:

  • Thick/heavy enough physical objects can block curses aside from the Killing Curse
  • Resonance between Harry's and Voldemort's magic more likely to harm/incapacitate Voldemort than Harry
  • Harry was instructed by Voldemort to cast Mahasu on any student in the classroom, chose himself. Foreshadows choosing to use promi
... (read more)
I don't believe leveraging Voldemort's bargain will work the way you suggest, because Parseltongue does not enforce promises, only honesty. When Harry demands that he himself be saved, Voldemort can simply say "No."
Right - but how low do you think the probability is, and what's the best action it displaces?
Sorry - hadn't logged in for a while. I thought it would have vanishingly low probability of working, though I don't believe that it displaces any other action likely to work (though it does displace saving a person if all else fails, which has nontrivial value). Having said that, curiously enough it seems that this particular suggestion WAS implemented in the official solution, so I guess that was that. :)
This also works well dramatically - it would effectively allow Harry to explain what he's doing as he's doing it.
Is Sirius a Death Eater in this fic? In canon, he was thought to be one, but he never was. Conversely, if he is a Death Eater in this fic, then why would he be Harry's ally? (And Harry knows none of this in any case.) ETA: Well, Harry does know the general reasons that everybody thinks that Sirius is a Death Eater. But he doesn't know why Sirius might be his ally, or why he might be called ‘Mr. Grim’ (which frankly is a bit extra-universe even to Sirius and Voldemort), or AFAICT why Sirius might not be locked up in Azkaban (since he had no reaction to hearing ‘I'm not serious!’ when he was there).
Wat We have not seen any first year cast that spell, and Harry suggested Wingardium Leviosa for how to retrieve the snitch-key.

We know that previous attempts by Voldemort to thwart a prophecy have backfired horribly. It therefore seems reasonable to assume that prophecies in HPMoR (as in canon) are self-fulfilling. (Warning: TVTropes-link!)

I therefore predict that Voldemort’s efforts to thwart this prophecy will counteract that intention and lead to the fulfillment of that same prophecy.

After 5 minutes of thinking about it, the only thing I could come up with concerns:


Bellatrix and Sirius are stars, and also Death Eaters. Voldemort has already torn apart Bellatrix to use the Dark Mark, and Harry can tear apart Sirius with the Partial Transfiguration trick people are talking about. How do we know Sirius is present? Because there is a Death Eater named "Mr Grim" who is stated to have known the Potters.

Hang on, isn't Sirius in Azkaban?

"I'm not serious, I'm not serious, I'm not serious..."

The "he" refers to both Tom Riddles, as they are branches of the same person.

Troubles with this suggestion:

The "HE IS THE END OF THE WORLD" part remains unresolved.

Narratively unsatisfying.

I think the literal physical stars are referred to. The centaur also thought the stars would go out:

"So the wandless have become wiser than the wizards. What a joke! Tell me, son of Lily, do the Muggles in their wisdom say that soon the skies will be empty?"

"Empty?" Harry said. "Er... no?"

"The other centaurs in this forest have stayed from your presence, for we are sworn not to set ourselves against the heavens' course. Because, in becoming entangled in your fate, we might become less innocent in what is to come. I alone have dared approach you."

"I... don't understand."

"No. You are innocent, as the stars say. And to slay something innocent to save oneself, that is a terrible deed. One would live only a cursed life, a half-life, from that day. For any centaur would surely be cast out, if he slew a foal."

Literal stars. Literally torn apart. The sun must be tamed. And more distant stars are also dangerous.

"End" can also mean "goal". This is somewhat interesting in light of EY's work at MIRI.
I don't think this is likely, if only because of the unsatisfyingness. However: Some foreshadowing on the idea of ominous-sounding prophecy terms actually referring to people's names. "blood spills out in litres" meshes well with "TEAR APART".
And then, since he's already figured it out when guessing about the Comed-Tea, Harry will make himself believe that the stars are the people, and so the prophecy means not him, but Voldemort, which is why if he does not stop Voldemort right now, he will fail to fulfill the Vow, which is impossible. So the Vow will work in his favor, possibly boosting his abilitiesto misdirect in Parseltongue. Also, Voldemort is aalready the end of the world, and has been since possessing the Pioneer Plague (which can be reached by phoenix at any moment). Also, Voldemort put on broomstick enchantments on his bones, and Harry already knows a way in which they are fallible: CRAP. NEWTON...
He didn't put them on his bones; remeber the part, where resurected Voldemort takes some sticks from Quirrell, attatches them to himself and tests flying? Voldemort would likely enchant his own bones later, but right now he has sticks attached to his limbs.
True, but what matters is if he attached the sticks stickily enough.
I like this, and you can resolve "HE IS THE END OF THE WORLD" by combining the rule that prophecies are meant to be heard by those they affect and to cause their consequences, and that to Voldemort, his death is the end of his world. So HE IS THE END OF THE WORLD is true for Voldemort, because Harry's killing power can be the end of Voldemort's world.
Is Sirius a Death Eater in this fic? In canon, he was thought to be one, but he never was.
About Sirius we only have the story from "Skeptical Wizard" (about Weasleys' rat) and some mentions in the Azkaban - nothing to suggest he was good.
True, but also nothing to suggest any changes from canon, where we were also led to believe him evil until The Reveal. Well, there is the possibility that someone in Azkaban is thought to be Sirius but isn't, which is a sign that Sirius may have imprisoned someone in his place, and that would be an evil act. But even if this is so (which it may not be), it may well be a justifiable act from the perspective of the Order of the Phoenix (for example, if Sirius imprisoned Peter in his place, and otherwise the characters are as in canon). Edit: Add the potential justification involving Peter (which is not an idea original to me, BTW).

Here is my stab at a solution (already posted at ffnet):

First Harry tells V. that Dementors are death, Patronuses work by not thinking about death and the true Patronus works by using a diferent mindstate which V. probably cannot attain (without specifics). Second Harry states that as long as Dementors are around every person including V have in each moment a small but finite probability to be kissed by one. Over an indefinite timeframe the aggregate probaility that V. is kissed approaches one. How this would interact with V's Horkruxes is unclear but he may easily suffer a fate worse than death. Therfore he should keep Harry around at least until the dementors are dealt with.

Then he points out that given what he knows about the ambiguity of prophecies the prophecy V. heard has probably not clearly identified that Harry and not V. is the threat. Thus V. killing Harry might easily doom the world. This is especially likely as V. is not bound by the vow. Thus V. should keep Harry around to guard against his own mistakes and probably take a similar vow. He himself may offer more vows to further Vs goals in exchange for V. vowing to further Harry's goals and so on. This should be benefi... (read more)

Another possible solution path:

"There iss already in motion a power which will desstroy world if left unchecked. [entropy] If you kill me, trap me, incapacitate me, or otherwisse hinder me, I will be unable to take necesssary possitive actionss to try to sstop it and ssave world. Am sstill bound by vowss, will not take any action I think will make desstruction worsse or more likely."

At which point the obvious next question for Voldemort to ask is, "What iss thiss power you sspeak of?", and then Harry would be pretty hosed. Moreover, if Voldemort discovers that Harry is trying to use tricky wording against him, he'll likely conclude (correctly) that Harry is not at all interested in being cooperative, and then kill him. The problem as I see is this: Voldemort is smart. Furthermore, he thinks like Harry, meaning that Harry's plans will be especially easy for him to see through. Any sort of successful verbal trickery would by necessity have to be something that Voldemort can't decode easily, which, given the constraints, seems to imply that the solution should involve domain-specific knowledge more than general intelligence, which in turn screams "Muggle knowledge!" to me. One example of this is the material implication trick I suggested (which I know you've already seen; I added the link there for other possible readers). Can anyone think of any other such tricks?
Why? Doesn't Voldemort have an interest in not allowing the heat death of the Universe to happen? We could change the framing so it's more of an explanation of entropy and heat death than an apparent trick (As I think some on Reddit have already done.), but I think this has a fair bit of potential at least as a tactic for buying time to partially transfigure something or for gaining access to Hermione if not for outright persuading Voldemort to let Harry out of the box.
Heat death is a long ways off, and in the long run, it's extremely unlikely that Harry is unique enough to play a crucial role in stopping it. Heck, Voldemort himself could read up on all the science Harry currently knows, a task that would take him at most eleven years, mostly like less (after all, Harry did it, and at a much younger age, too), and be at least every bit as well-suited as Harry is right now at stopping heat death, and probably much more well-suited seeing as he knows more magic. (Plus, eleven years on a cosmic scale is less than the blink of an eye.) I don't think Voldemort would consider the (very probably minimal) value Harry has to offer in preventing the heat death of the universe enough positive utility to outweigh the fact that a prophecy said he would tear apart the very stars in heaven. That is not to say, however, that this entire line of thought doesn't work. If Harry has something to offer Voldemort that he would actually value highly enough to consider letting him live, then we're in business. Off the top of my head I'm not thinking of anything, but it's a definite possibility. (Intelligence enhancement, perhaps?) Still, I don't think the "help stop heat death" offer is going to be the winning method.
My final solution, already submitted as a review to

Haven't seen this solution elsewhere: I think it's actually strong on its own terms, but doubt it's what Eliezer wants (I'm 90% sure it's about AI boxing, exploiting the reliability granted by Unbreakable Vows and parsetongue)

However, this being said, I think Harry could avoid imminent death by pointing out that if a prophecy says he'll destroy the world, then he presumably can't do that dead. Given that we have strong reasons to think prophecies can't be avoided, this doesn't mean killing him is safe, but the opposite - what Voldemort should do is make him immortal. Then the point at which he destroys the world can be delayed indefinitely. Most likely to a point when Voldemort gets bored and wants to die, after the heat death of the universe.

This isn't a great solution for Harry, because the best way to keep him alive would be paralysed/imprisoned in some fairly extreme way. But it should hit the criteria. The one really big point against it is that all this info is very available to Voldemort, so not sure why he hasn't come up with it himself.

I am the only one quite upset about this and thinking it's mean from Eliezer ? There are at least three kind of reasons that makes me upset :

  1. It breaches an implicit contract between readers and authors. Especially when it's such a long work, each reader has invested literally hundred of hours to get to this point. Asking us to do something to get the real ending, that's already written, at this point is a kind of blackmail. And the only long-term answer to blackmail, as Dumbledore explained in HPMOR, is to not comply.

  2. What purpose does it serve, apart doing harm ? The purposes of HPMOR, in my understanding, are : 1. Bring awareness (and therefore, among other things, money/donations) to MIRI/CFAR. 2. Show people that rationality is awesome so they'll read more about it (ie, the Sequences, books, ...) and therefore "raise the sanity waterline". This undermines 1. by pissing off part of the reader base and making the story suboptimal, and this greatly undermines 2. if the super-rational Harry still fails.

  3. It's not a fair nor fun game at all, because there is so much we don't know about the laws of the settings, so we are reduced to blind guesses. We don't know how fast

... (read more)

I don't think it's unfair at all, but your comment made me rethink something that may be relevant. Quirrel set a surprise exam, and it was surprisingly easy and everyone (except Hermione) passed. I think probably the worst thing that you can do in the face of a surprise exam is not attempt to answer, and maybe that's part of the lesson EY is trying to convey here :-)

I also note that Quirrel failed Hermione in the knowledge that he would be resurrecting her, and this is either very mean, or a very good lesson for resurrected Hermione, or both.

Clearly enough people disagree, given the amount of interest and lack of condemnation in /r/hpmor, here and in ##hpmor.
Two hashes?

Harry is allowed to solve this problem any way YOU would solve it. If you can tell me exactly how to do something, Harry is allowed to think of it.

This is not quite phrased correctly. While I know less magic than the protagonist (having not attended Hogwarts for a year), I know far more physics and mathematics than he does. I am also privy to world-building knowledge that he isn't. For example, we know about major artefacts:

  • The Elder wand has been repeatedly featured in the fic, but neither Harry!Riddle not Voldemort!Riddle are aware of it yet.

We also know little trivia:

  • Tom Riddle's middle name in this AU is Morfin, not Marvolo. Knowing canon this tells us something about Merope Gaunt's relationship with her father and brother.

In conclusion: it's not enough for us to think of a solution, we also need to explain how Harry can think of it. There's no point in simulating Harry's smarts on my hardware, I can use my own smarts. But I do need to simulate Harry's knowledge.

Similarly, it would be seriously pushing it to rely on any scientific advances of the last (real-world) decade or so, unless there's a reason Harry would be able to at least semi-plausibly pre-discover them himself. Not that I can think of any of those which would help anyhow, but it's something to keep in mind. Future tech - even things we think we could perhaps do - is probably right out. Harry could conceivably transfigure something (his epidermis, for example; has anybody mentioned that yet?) into a material that we know exists or could exist, and can describe in atomic or sub-atomic detail, yet can't synthesize; an arbitrary isotope of an arbitrary element should probably be possible, for example. He can't use transfiguration to produce something with negative mass (, though... at least, I would assume not, even if the science he knows suggests that such a thing is theoretically possible.

Not a solution, but should the Death Eaters be discounted as not good for much of anything?

I don't just mean that Voldemort has shown them to be fairly incompetent, but that they may be too shaky to use whatever remains of their skills.

As an orthodox Discordian, I would be very pleased if it turned out that one of the Death Eaters has an idea which would be very useful for Voldemort, but is too afraid to say it.

What's the difference between an orthodox Discordian and a heretical one?

Heretical ones actually follow the written holy books.


This is your final exam.

You have 60 hours.

Your solution must at least allow Harry to evade immediate death, despite being naked, holding only his wand, facing 36 Death Eaters plus the fully resurrected Lord Voldemort.

If a viable solution is posted before *12:01AM Pacific Time* (8:01AM UTC) on Tuesday, March 2nd, 2015, the story will continue.

Otherwise you will get a shorter and sadder ending.

There are more details and suggestions at the end of the chapter.

Question for Eliezer: Would a post to a LessWrong HPMOR discussion thread count as a solution, or must all solutions be posted to

Keep in mind the following: 1. Harry must succeed via his own efforts. The cavalry is not coming. Everyone who might want to help Harry thinks he is at a Quidditch game. 2. Harry may only use capabilities the story has already mentioned; he cannot develop wordless wandless Legilimency in the next 60 seconds. Of course, Harry may find more clever ways to use abilities he has already been established to have. 3. Voldemort is evil and cannot be persuaded to be good; the Dark Lord’s utility function cannot be changed by talking to him. 4. If Harry raises his wand or speaks in anything except Parseltongue, the Death Eaters will fire on him immediately. 5. If the simples timeline is otherwise one where Harry dies – if Harry cannot reach his Time-Turner without Time-Turned help – then the Time-Turner will not come into play. 6. It is impossible to tell lies in Parseltongue. Within these constraints, Harry is allowed to attain his fully potential as a rationalist, now in this moment or never, regardless of his previous flaws. Of course, ‘the rational solution’, if you are using the word ‘rational’ correctly, is just a needlessly fancy way of ‘the best solution’ of ‘the solution I like’ or ‘the solution I think we should use’, and you usually say one of the latter instead. (We only need the word ‘rational’ to talk about ways of thinking, considered apart from any particular solutions.) And by Vinge’s Principle, if you know exactly what a smart mind would do, you must be at least that smart yourself. So what I mean in practice, when I say Harry is allowed to attain his fully potential as a rationalist, is that Harry is allowed to solve this problem any way YOU would solve it. If you can tell me exactly how to do something, Harry is allowed to think of it. But it does not serve as a solution to say, for example, “Harry should persuade Voldemort to let him out of the box” if you can’t yourself figure out how. … I wish you all the best of luck, or rather the best o
March 2nd isn't a Tuesday; is it Monday night or Tuesday night?
It clearly stipulates 12:01 am to avoid just this kind of confusion. Further, the chapter will be posted at 10:00 am on Tuesday. So the deadline is Monday night.
The available dates were Monday, March 2nd, or Tuesday, March 3rd; the "12:01 am" did not distinguish which of those dates was meant by "Tuesday, March 2nd" in the slightest, since both possible dates had their own 12:01 am. This has been subsequently corrected by EY to "Tuesday, March 3rd" (which was the correct day for the 60 hours promised).
The tradition in timetables is to list 11:59 pm for endings (such as we have here) and 12:01 am for beginnings. Eliezer should have followed the tradition; the evidence for my claim is that janos was confused when EY violated the tradition. (Edit: Well, actually, janos was apparently confused by a bona-fide error, not by this.)
Another question for Eliezer: can this solution involve some past preparations not explicitly seen on camera? Like, can we say "Harry has a Weasley-provided pink plastic flamingo in his pouch, which he can use to defeat 37 Death Eaters in the obvious fashion."
I would say no to the Flamingo, but yes to any object ever mentioned in the story (e.g. car engine that he tried to use in the first battle), after all, Harry prepared his pouch for anything and everything that he could fathom.
In pouch, no. Transfigured in his glasses, maybe... but Harry is not allowed to move his hands to touch the glasses. Unless the glasses already a contain a killing machine operated by eye movements. Then Harry can kill everyone with a blink of an eye. (Undiscriminate killing would also hit Hermione, but she would survive.)
Since they are touching his skin, does he need his wand to cancel the Transfiguration?
No. He just learned to dispell Transfiguration without a wand when he dispelled the one on Hermione's body.
in that case he'd have used that in Failure Pt 2 obviously.

Its possible that the solution will have multiple steps, such as:

1) Stall for time by giving information on useful powers

2) Demand that vow requires Hermione is awakened so Harry can discuss the probability of him ending the world.

3) Hermione causes a distraction by slitting her wrists and running round shouting "Look at me! I'm bleeding silver blood everywhere but I'm not dying! How can it be?"

4) Harry triggers resonance cascade

5) Harry transfigures weapon

6) Harry kills everyone

7) Harry, badly wounded, drinks Hermione's unicorn blood to save him from death, killing Hermione in the process

8) Hermione comes back from the dead because of the Horocrux

9) Hermione uses the philosophers stone to permanently transfigure them both into unicorns

10) HPMOR turns into Harry Potter/MLP:FiM crossover fanfiction

Now, my question is this: does one review have to get every step absolutely correct? Or is it ok if ten reviews each get one step correct? What if a review starts "first stall for time - many other people have submitted excellent ideas for this, which I shall defer to."?

In other words, Bad Ending.
If Harry defeats Voldie because Voldie took every possible precaution except disarming Harry ... I'm worried we might have a huge plot hole ending.

I can think of a solution, but may not be the solution because it relies on untested extensions of previous mechanisms having to do with "Dementers" which HarryPrime knows to be magical incarnations of death, that obey people's expectations about death. Critically, it depends on how much play he has in the distance and plasticity of dementer control.

My plan probably requires him to have put it into motion during the text we already read. Imagine that when he was surrounded at the end of chapter 112 at this moment, he put his plan into motion:

You know, said the last voice within Harry, the voice of hope, I think this is getting pretty bad even by my standards.

Right after that, he could have started expecting 40 dementers to arrive at his location without disturbing or being seen by anyone while traveling, so it doesn't change anything already known about the world before he time turned already.

He expects them to arrive in a group, and to kill everyone but him and Hermione, even if he himself has already been killed (this last clause might not work, depending on how the magic about dementer expectation control works). He expects the dementers to travel at a poetica... (read more)

You should look at reddit to coordinate your actions with others. One idea I like is to organize the proposal of all reasonable ideas and minimize duplication. Organization thread here:
Thanks for the URL :-)

Oh, interesting. EY just asked his readers to solve an impossible problem. I wonder how many will feel they have enough at stake here to actually pay the mental and emotional tax involved in solving impossible problems, to maintain that awful tension. I mean, at the end of the day, it's a fanfic on the Internet.

I sure hope the problem looks easier to some smarter readers than me, because it's gonna be silly from a promotion-of-rationality angle if the addition of rationality to Harry Potter changes the outcome from "hero wins" to "hero dies and people he cares about get horribly tortured to death".

Thought some more, and I have some ideas.

One of the realizations I think I had is that magic recognizes divisions where there are none. PT being the prime example, but also the ability of armor to block spells. PT relies on removing the caster's understanding of divisions; what if there is a way to add divisions? If Harry can convince himself that his skin is not part of himself, will it block spells the way thick leather does?

Conversely, are there other divisions that open possibilities if removed? Like between people and the ground, or people and people?

Most thinking I'm reading about uses PT to create a weapon with which to attack, but attack is not the goal. Escape is. Means of escape fall into a few categories, I think: Figuring out something like Apparition on the spot, quantum tunnelling, or Newtonian. Right now I'm just going to think about "newtonian" - It's just as ridiculous for transfiguration to not include velocity as it is for it to only effect "discrete" objects. Can Harry simply add enough velocity to himself to escape? (Adding acceralation doesn't work, as enough to escape fast enough probably squishes him)

Here are crazier things:

  • There's good

... (read more)
The Map says that Harry is Tom Riddle. So although it probably doesn't satisfy Eliezer, since you could say it is not "avoiding immediate death" in the physical sense, and it is not through his own efforts (Eliezer's stipulation), in reality the ending in which he survives could simply be they kill him as planned, he ends up in Tom Riddle's Horcrux network and can go and propose to someone that he take over his body at least temporarily.

Can we each propose a non-transfiguration solution? Even if it's just a rough idea. I feel like we're getting stuck on transfiguration, and a bunch of those require very precise handling of things 10 feet away (such as death eaters) or significantly big things (Harry's body parts). Hermione struggled to get the stunning hex right on the first try, and I feel Eliezer will categorize "transfigure this very precise, remote thing" as a "new magical power".

Stratagem (1) State something that is true, but that LV won't believe. Either LV thinks you've broken the Parseltongue curse, or you gain time in the confusion. Him thinking that you've broken the curse gives you a power he knows not that you can bargain/threaten with. Sub-suggestions: "Sometimes we make our own phoenix tears" (when asked why he told his friends to refrain back near the start) ; "The solar system will die in 10 billion years and you will be forever alone" ; "Hey, you know how you forged a time-turned letter? Well, it didn't actually include my code-word for time-turned messages... I wonder if the great Lord Voldemort can predict what will happen now?" (not a lie). And someone else made the suggestion of making statements that have a true consequent so that you can make up the antecedent along the lines of "If you destroy me now, the sun will die, and the starts blink out one by one. I know not when, but it shall cause you great grief and misery teacher. If you allow me to live, shall keep them alive for as long as I can, remember my vow"
I've been wondering for a while now: can you say Ththiss ssentensce iss a lie! in Parseltongue?
I would expect the last word to turn into "paradox" in the same sort of word as the last word in Harry's test turned into "four".
You can't say 2+2=3, so no. You will input the word 'true' as the simplest fix.

The Parseltongue statement must be a critical part of the upcoming solution, I think. Simply killing the Death Eaters will not do; they are, as Voldemort puts it, useless. (That is, a solution that disables the Death Eaters but not Voldemort is not a solution.)

The text of the boundary conditions suggests that Harry can't change Voldemort's values, but the lesson suggestion makes clear that he can change Voldemort's beliefs.

I think the first thing for Harry to suggest is that the prophecy is being misinterpreted. The trouble with this is he needs to hear t... (read more)

Harry can talk to LV about the life cycles of stars and the heat death of the universe. All this could force LV to rethink what it means to be immortal when the sun engulfs the earth or the universe hits maximum entropy. This could buy some time.
I agree that this would be relevant, but Harry doesn't know the literal text of the prophesy yet. Only discussion of "destroying the world" has happened in his presence, not "tear apart the stars". The fact that "protecting the earth" in the very long run requires protecting the earth from solar flares and supernovas hasn't yet been understood by Voldemort.
Sorta ties into something I thought about much earlier; -- The easiest way to prevent LV from killing HP would be for HP to convince LV that his intention is misguided. -- His intention is to kill Harry to save the world. (funny, that) -- Killing Harry will not save the world. It is clear that LV is aware of this, based on his reflections on self-fulfilling prophecies. -- LV intends to defy the prophecy at every point of intention, and will therefore try to kill HP anyway, because if the prophecy is coming true anyway he's already screwed and has nothing to lose. -- Convincing LV that killing HP is useless is therefore insufficient. He must be convinced that killing HP will bring about the very thing he wishes to avoid. -- HP's existence must be tied to the continued well-being of the world. -- What does HP have that could save the world? Well, power over dementors. -- What might dementors do that could destroy the world? Jump into the sun, perhaps? -- The realization that that would be an optimal thing for death incarnate to do will cause the thing itself to happen. -- Unfortunately, the vow cannot prevent this, because it allowed for the weighing of risks, which by nature includes contemplation of disastrous possibilities. (if I die, does this end the earth? Is it dementors? if I don't think about this question, and they've done something, that's a certain bad thing, but if I think about it, I might decide there's nothing wrong and that's a not-certain bad thing, so I'll take the lesser risk and think about it.) -- HP is the only one who can stop them from destroying the sun. And if he dies, he cannot prevent them from doing so. -- Not that killing HP would be intelligent in any case, as there's a non-zero chance that his death and subsequent entrance into the horcrux system would kill LV too. I'm very interested in commentary.
I don't think Harry would automatically consider Dementors jumping into the Sun an optimal thing to do as there are too many unknowns. * Can a Dementor fly high enough or fast enough to leave the Earth's atmosphere? Practically speaking, we don't know how much of their flight is true flight and how much they are bound by forces like gravity (not as much as true material beings, obviously, but that's not necessarily the same as not at all). * Can a Dementor survive away from the Earth? We don't know if they need to absorb sustenance. It may be that they need to draw on the Earth's ambient magical field to continue to exist, or to remain within a certain range of living beings with thoughts and feelings to passively absorb. It may be that shadows of Death have no meaning too far away from the nearest living thing. * How long would it take a Dementor to reach the Sun? We don't know their maximum travelling speed, but you can Apparate away from them, and the journey might easily take long enough for humanity to achieve magico-technological singularity in the meantime, or for cosmic-scale Patronus casting to become a thing, or any number of other solutions to be implemented. * Can Dementors destroy the Sun? Azkaban is still standing despite having a significant concentration of Dementors in it for at least decades, and we know it's not because it's magically protected, since Dementors consume magic. It's plausible that all the Dementors on Earth will not have a sufficient impact on the Sun's lifespan to make a difference to humanity.
My suspicion that they would destroy the sun has more to do with their action as potential heat sinks due to their indestructibility than their drain abilities.
He does know that a prophecy said something about 'tearing apart the very s-' AND that a centaur was concerned about the stars all going dark. Stellar shenanigans seem like a very likely culprit.
Exactly my thought. Aaaaand there was mention of apparating one into the sun.

Question for EY:

In the chapter, you wrote:

If a viable solution is posted before 12:01AM Pacific Time (8:01AM UTC) on Tuesday, March 2nd, 2015, the story will continue.

Does this mean that the reader-suggested solution will in fact be used, or will the story simply continue with the solution you originally had in mind?

How many months do you want to wait until Eliezer rewrites the story to match the reader-provided solution?

Fair enough. The phrasing caught me a bit; that's all.

Pessimistic Assumptions Thread

"Excuse me, I should not have asked that of you, Mr. Potter, I forgot that you are blessed with an unusually pessimistic imagination -"

Ch. 15

Sometimes people called Moody 'paranoid'.

Moody always told them to survive a hundred years of hunting Dark Wizards and then get back to him about that.

Mad-Eye Moody had once worked out how long it had taken him, in retrospect, to achieve what he now considered a decent level of caution - weighed up how much experience it had taken him to get good instead of lucky - and h

... (read more)
Pessimistic assumption: Voldemort has made advance preparations which will thwart every potential plan of Harry's based on favorable tactical features or potential features of the situation which might reasonably be obvious to him. These include Harry's access to his wand, the Death Eaters' lack of armor enchantments or prepared shields, the destructive magic resonance, the Time-Turner, Harry's other possessions, Harry's glasses, the London portkey, a concealed Patronus from Hermione's revival, or Hermione's potential purposeful assistance. Any attempt to use these things will fail at least once and and will, absent an appropriate counter-strategy, immediately trigger lethal force against Harry.
Pessimistic assumption: Voldemort wants Harry to defeat him on this occasion. To get the best ending, Harry must defeat Voldemort, and then, before leaving the graveyard, identify a benefit that Voldemort gains by losing and deny him that benefit.
Pessimistic assumption: An intended solution involves, as a side-effect, Harry suffering a mortal affliction such as Transfiguration sickness or radiation poisoning, and is otherwise highly constrained. The proposed solution is close to this intended solution, and to match the other constraints, it must either include Harry suffering such an affliction with a plan to recover from it, or subject Harry to conditions where he would normally suffer such an affliction except that he has taken unusual measures to prevent it. (This is one reading of the proviso, "evade immediate death".)
Pessimistic assumption: Voldemort has reasonable cause to be confident that his Horcrux network will not be affected by Harry's death.
Pessimistic assumption LV has been planning exactly this conversation for months and has thought of every possible plan of action that he could do. He has Harry level intelligence. All viable solutions must therefore use information LV does not have access to, which does not include the fact that Harry is Tom Riddle. Asking for power he knows not is trying to patch this minor hole.
Pessimistic assumption: The effect of the Unbreakable Vow depends crucially on the order in which Harry lets himself become aware of arguments about its logical consequences.
And not only Harry must not interrupt the game, he must prevent everyone else who do not know he's Time-Turned from doing it.
Pessimistic assumption: Any plan which causes the occurrence of the vignette from Ch. 1 does not lead to the best ending. (For example, one reading of phenomena in Ch. 89 is that that Harry is in a time loop, and the vignette may be associated with the path that leads to a reset of the loop.)
Pessimistic assumption LV knows that Harry can do partial transfiguration. LV has put up anti- apparition, anti- time turning and anti-transfiguration wards. Less probable Pessimistic assumption these wards do not count as LV's magic once laid and will not resonate with Harry, meaning they will stay active. Alternatively, a death eater has laid them on previously understood instructions.
Pessimistic assumption: Voldemort can reliably give orders to Death Eaters within line-of-sight, and Death Eaters can cast several important spells, without any visible sign or sound.
Pessimistic assumption: Voldemort wants Harry to reveal important information as a side effect of using his wand. To get the best ending, Harry must identify what information this would be, and prevent Voldemort from acquiring this information.
Pessimistic assumption: Hermione, once wakened, despite acting normal, will be under Voldemort's control.
(somewhat shaky) Pessimistic Assumption Voldemort can use a Time-Turner, too, and he will send himself a message from the future to win.
Concerning Transfiguration:
Pessimistic assumption: Neither partial Transfiguration nor extremely fast Transfiguration (using extremely small volumes) circumvent the limits on Transfiguring air.
Pessimistic assumption: Harry's wand is not already touching a suitable object for Transfiguration. Neither partial Transfiguration nor extremely fast Transfiguration of extremely small volumes lift the restriction against Transfiguring air, dust specks or surface films would need to be specifically seen, the tip of the wand is not touching his skin, and the definition of "touching the wand" starts at the boundary of the wand material.
Pessimistic assumption: Free Transfiguration doesn't work like a superpower from Worm: it does not grant sensory feedback about the object being Transfigured, even if it does interpret the caster's idea of the target.
Pessimistic assumption: At least in the limit of unusually thin and long objects, Transfiguration time actually scales as the product of the shortest local dimension with the square of the longest local dimension of the target, rather than the volume. Harry has not detected this because he was always Transfiguring volumes or areas, and McGonagall was mistaken.
In Azkaban is stated that Harry transfiguration of a thin cylindrical layer from the wall is fast because its volume is small. This seems to contradict your assumption.
Pessimistic assumption: Voldemort, and some of the Death Eaters, have witnessed combat uses of the time-skewed Transfiguration featuring in Chapter 104. They will have appropriate reflexes to counter any attacks by partial Transfiguration which they could have countered if the attacks had been made using time-skewed Transfiguration.
Pessimistic assumption: It is not possible to Transfigure antimatter.
Pessimistic assumption: Plans which depend on the use of partial Transfiguration, or Transfiguration of volumes small enough to complete at timescales smaller than that of mean free paths in air (order of 160 picoseconds?), to circumvent the limitation on Transfiguring air, will only qualify as valid if they contain an experimental test of the ability to Transfigure air, together with a backup plan which is among the best available in case it is not possible to Transfigure air.
Pessimistic assumption: Plans which depend on Transfiguring antimatter will only qualify as valid if they contain an experimental test of the ability to Transfigure antimatter, together with a backup plan which is among the best available in case it is not possible to Transfigure antimatter.
Pessimistic assumption: There are more than two endings. A solution meeting the stated criteria is a necessary but not sufficient condition for the least sad ending. Note that the referent of "Ch. 121" is not necessarily fixed in advance. Counterargument: "I expect that the collective effect of 'everyone with more urgent life issues stays out of the effort' shifts the probabilities very little" suggests that reasonable prior odds of getting each ending are all close to 0 or 1, so any possible hidden difficulty thresholds are either very high or very low. Counterargument: The challenge in Three Worlds Collide only had two endings. Counterargument: A third ending would have taken additional writing effort, to no immediately obvious didactic purpose.
A necessary condition for a third ending might involve a solution that purposefully violates the criteria in some respect.
Semi-pessimistic assumption: Harry is in the Mirror, which has staged this conflict (perhaps on favorable terms) because it's stuck on the problem of figuring out what Tom Riddle's ideal world is.
Pessimistic assumption: Voldemort evaded the Mirror, and is watching every trick Harry's coming up with to use against his reflection.
Pessimistic assumption Voldemort should not be killed, since without him it will never be known if the Prophecy came true.

Eliezer gave a hint of the solution in chapter 5:

"You triumphed over the Dark Lord by being more awful than he was, and survived the Killing Curse by being more terrible than Death."

Death is the Destroyer of Worlds, but Harry is the Destroyer of Stars!
Right now it seems more like a hint of the problem.
So what you're saying... is that Harry should sing?

Observation: If the purpose of this exercise is to run an AI box experiment, with EY as gatekeeper and the internet hivemind as the AI, then the ability to speak in parseltongue is problematic: It appears to make the game easier for the AI, thereby preventing the results from being generalized to a standard AI box experiment.

So why did Eliezer include the parseltongue constraint?

Maybe parseltongue is meant to introduce the concept of provability in a way that everyone can understand. To speak in parseltongue in real life, you just speak in logic statements... (read more)

It's there to limit Harry using the death eaters somehow. Seriously, my first thought on this problem was to convince the death eaters that there were two Voldemorts to seed confusion.

Planning thread over at /r/HPMOR for centralized discussion. It's probably better to have segregated groups working on this, but I don't really think that'll be a problem.


If you have any remotely good idea, post it as a review. The currently extant ones are awful. Most don't even make sense.

I like the one about causing a nuclear holocaust by splitting one atom.
My favourite so far have been the reviews that are actually reviews. There's one that accuses EY of breaking the TOS, which does not permit "choose your own adventure" stories.... headdesk

I regard fighting as futile (can't speak magic without death eaters attacking, can't cast worldess magic without Voldemort sensing through resonance and shooting). Harry must lose.

Voldemort is only killing him because of the prophecy. Harry should ask to hear the prophecy, so that if he is ever reborn somehow he can avoid it. Voldemort will probably tell him, hard to think how giving information about the destruction of the world to Harry could hurt it, since he's taken the Vow and now can only threaten the world through ignorance.

Once Harry hears the p... (read more)

I don't think that's a foregone conclusion, and not one Harry would be willing to bet his life and the fate of the universe on. Voldemort specifically said that he doesn't want to tell Harry because telling him could make it come true. Harry has to convince Voldie that it's not just okay to tell him, but beneficial to his goals to tell him. That's the kind of argument you'd have to craft here.
It could have made it come true BEFORE the Vow. Now Harry, having Vowed, is only ever a danger to the world through ignorance. Increasing his knowledge cannot increase the danger he poses the world.
I agree. This is a good line of reasoning. I was just saying that Harry has to make that argument and it's not guaranteed LV will accept it.

Why hasn't Voldemort suspended Harry in air? He floated himself into the air as a precaution against proximity, line of sight problems, and probably magics that require a solid substance to transmit through. If Harry were suspended in air partial transfiguration options would be vastly reduced.

Why hasn't Voldemort rendered Harry effectively blind/deaf/etc. - Harry is gaining far more information in real time than necessary for Voldemort's purposes?

Also, it seems prudent not to let Harry get all over the place by shooting him, smashing him, etc. without... (read more)

Why doesn't LV tell one of the DEs to finite incantatem HP's glasses?

and tell Harry to drop his wand now that the Vow is over, otherwise the other Death Eaters kill him.
happenss next chapter, of coursse. readerss should be ready for Voldemort to adapt in wayss not explicity sstated—Voldemort has intelligence to do sso.

Posted on Harry realizes that his true power the Dark Lord knows not is his ambition to master the fundamentals of magic, in contrast with how proud of himself Voldemort was for developing one original ritual. Harry cannot explain this to Voldemort-that would go against his Vow. However, he can drop some very juicy teasers in Parseltongue; in particular, he can imply that his secret holds the cure to Voldemort's ennui. It might go something like (in Parseltongue):

"Though you are ambitiouss, you have no ambition. That iss true power Dark Lord k... (read more)

My model of Voldemort is highly risk averse when it comes to existential risk. His response to this is to laugh at having been told he has no ambition, then to kill Harry. Voldemort trusts himself not to destroy the world, just the same way as Harry trusts himself. Maybe we shouldn't be so trusting of either.
Could he really laugh off such an accusation made in Parseltongue? If Voldemort thinks Harry is sincere but mistaken, Harry should follow up by noting that his hidden ambition was key to Patronus 2.0, the fundamental law of potions (probably known to V but discovering at age 11 is impressive even for a RIddle), and partial transfiguration, revealing as little as possible but as much as necessary.
Accusations in Parseltongue are not true, the speaker merely believes them. (Actually, this raises the possibility of lying using a confundus charm. I'll assume that's banned by some Rule). If you were trying to mitigate the chance of someone destroying the world, you place a very high probability on them trying to trick you. The response is to use Hermione's algorithm that defeated LV earlier and place an ethical injunction on not killing Harry. Now, that's probably a little harsh for the exam question, and LV won't necessarily adopt his enemy's tactic (even though it defeated him once and that's one of his rules), but I should think he requires substantial evidence to not kill Harry. More than an accusation of not being ambitious, which is explained by Harry's naivety.
I very much doubt that the power the Dark Lord knows not is ambition. See: chapter 70.
From a prophecy sense, no. On the other hand, telling Voldemort that he is insufficiently ambitious, and having arguments to back that up, would really sting, and make him more likely to engage with the idea rather than just brushing it off and forcing Harry to go back to the original interrogation.
I'm throwing Quirrell's very words from that chapter in his face :). It doesn't sound like he has a clear idea of what to do with the world after he achieves domination of it. If Harry can't quite say in Parseltongue that the Dark Lord has no ambition, he can nevertheless be confident that the particular ambition of discovering the magical theory of everything is unique to HJPEV. I think it's reasonable to call this his true hidden power, as it's the meta-power behind his invention of partial transfiguration, and a key ingredient in his power over Dementors (expecting death to be solvable). I suspect his honest answer to whether V would ever discover this ambition is that he doesn't know.
No-one's ever asked. He might have lots of plans. And while he claims he doesn't enjoy things (other than killing idiots), and so it could be argued he only acts to prevent bad things but has no positive ambitions, I think this is false. He was visibly, emotionally proud about his Great Invention. He enjoyed fighting the Wizarding War so much he postponed winning, and he laughed when he defeated Dumbledore. I put a high probability on him having lots of concrete ideas for two days from now. On the contrary, when Harry asked Quirrel about the nature of magic, Quirrel said there was dozens of non-secret theories. Which means lots of wizards spent time inventing them. Which means many wizards shared this ambition - which seems very natural. So it certainly isn't an ambition LV doens't know about. And I don't think you can call an ambition LV knows about and has seen in many people, but doesn't happen to share, a power he knows not.

Harry needs to lose. He needs to drop his wand, kneel down, and say in Parseltongue, "I loosssse." Quirrel has already set up several tests that Harry has failed by refusing to lose. By proving that he can indeed lose, instead of continuing to escalate the conflict until the stars themselves are at risk, he may be able to pass LVs final test.

Surely following Voldemort's exact instructions and giving up his secrets would equally count as losing, without risking annoying Voldemort and getting killed or punished if your hypothesis is wrong?
Of course, that would count as losing as well. I just think he needs to explicitly acknowledge that he is losing, so that Voldemort doesn't think he is secretly plotting something else. I'm just worried that this is all a big setup, and the 37 "Death Eaters" are really Harry's allies in disguise and Imperiused, so any attempt to get out will cause Harry to end up killing all of his friends and put him on the true path towards destroying the stars. There was enough potential foreshadowing for this to be true. -They aren't wearing the correct battle armor, only a hastily transfigured replica. -LV explicitly said he expected Harry's friends to show up later than they did (which could mean they were supposed to be there for this ritual). -The two main ones I've heard people talk about seem to be Lucius Malfoy and Sirius Black, both of whom are arguably now Harry's allies.
They all showed up when the Dark Mark was called, only one of them has a transfigured mask replica, and no Death Eaters are likely to be allies to Harry since Voldemort can apparently just will them into seven smoldering pieces at any time.
Yes, but who called the Dark Mark, and pointed out the transfigured mask. It could all be a ruse by LV. Constant Vigilance!

I have a way of escaping that uses an item that has been established.

A: In the interest of keeping it simple the thing the most obvious answer for something Harry can do that he in theory could teach Voldermort/keep him talking is partial transfiguration.

B: Once Harry tells Voldermort that he can partially transfigure things, Voldermort will want to know the words/motions. Harry can say that he can teach Voldermort (he can't teach him how to cast a Patronus due to Voldermort's lack of love and he can't teach him how not to fear the death the way Harry doe... (read more)

In chapter 104 we have this: "Harry had refreshed the Transfigurations he was maintaining, both the tiny jewel in the ring on his hand and the other one, in case he was knocked unconscious". The other one was Hermione's body. This suggests that the glasses are not a transfigured item.
Okay the new plan works like this. Harry will say in Parseltongue that he will transfigure two objects, one to show the basic principles, one to show the more advanced applications of it/what you can do after you master the skill. Either of the objects he will be transfiguring materials into will have any magical properties, they will not allow him to kill Voldermort, and they will not allow him to magically escape the graveyard. Harry will then transfigure his glasses (using the hold in one hand method I described in the first plan), to change just the color of the lenses to black, without changing the color of the rims, legs or any other part. He will confirm that this was transfiguration and not some other simple charm to Voldermort and ask if he is interested in learning more about this power. Then he will need to transfigure a section of the ground into the most powerful and most harmless looking flashbang grenade. At that point he simply needs to release his transfiguration in the right way (if he can control how something approaches the end point as he transfigures it, just reverse that skill and you can choose how it looks as his transfigured control of it fades away not a new power just a new use for an old one) so as to pull the pin on the grenade. The change to his glasses will prevent Harry from being blinded though he will still be deafened. This won't be too much of a problem though because we've already seen him command his pouch with hand signals. With the Death Eaters unable to see him, and possibly having more difficulty casting spells as well (thanks to being unable to hear themselves talk meaning they may screw up the verbal components to their spells) and Voldermort likewise unable to see him and reduced to firing blindly.... Harry has a decent chance to making it to his pouch, if he has the magic to summon it to him so much the better, if not just run like f*. Then he needs to tell the pouch to give the king of hearts, and tear it up w
Thank you for pointing that out let me reconsider and revise..

Voldemort is going full Bond villain and talking when he should be killing. I figure I'll have to sleep on this problem, but here are some observations:

  • Harry can't speak with the Death Eaters. We haven't been told of a secret Parselmouth among them, so any conversation will be intelligible only to Harry and to Voldemort.

  • Voldemort can periodically ask in Parseltongue whether Harry is doing anything to try to escape, and a refusal to answer would likely result in a swift death.

  • It has been pointed out in canon that a good Legilimens can detect when some

... (read more)
Harry has some power that Voldemort knows that, that very possibly could die with Harry. It seems like the right play for Voldemort to let him talk for a bit. It was about an hour. Somewhere between three and four hours remain until someone Harry leaves, and it may be further until someone notices that he is gone.
It's June 13, 1992. The moon had already risen by the time they got to the graveyard ("The moon above was over three-quarters full, already seeming bright with night not fully fallen." Ch. 111). Hogwarts is located in Scotland, and the moon tables for that date show that in Glasgow, the moon rose at 8:48 pm, local time. It's not quite dark yet. The resurrection of Hermione and Voldemort recovering his body take some time. By the time the Death Eaters arrive, it's night ("The gibbous moon riding higher in the cloudless sky, the stars and wash of the Milky Way visible in all their majesty within the darkness" Ch. 113). At that date the sun set at 10:03 pm in Scotland. Now, at 11:04 Harry checks his watch and shortly thereafter receives the (fake) message. Harry goes back in time 5 hours and is confirmed to be in the past at 6:45 (11:45 future time). I don't know how long it took to possibly talk to Cedric and walk all the way back to the castle and make it to the third-floor corridor in time. If he gave himself some 10-15 minutes travel time, he's got at most an hour and a half before his departure from the Quiddich field.

I shall take no chances... in not destroying the world...

Oh my... did Voldemort just magically imbued Harry to do his best to put the whole world into time-frozen stasis in the Mirror?

Though revealing this to LV would not do any good - there is a failure safe mode, namely killing Harry, and if LV learns what he did (apart from pointing out his own stupidity), he has all the motivation to kill Harry right now.

Skimming over (part of) the proposed solutions on has thoroughly destroyed any sense of kinship with the larger HPMoR readership. Darn, it was such a fuzzily warm illusion. In concordance with Yvain's latest blog post, there may be few if any general shortcuts to raising the sanity waterline.

I don't see how there could possibly be a real solution. No matter what Harry offers Voldemort -- for example even if he offers to make an Unbreakable Vow to devote himself to serving Voldemort's purposes -- Voldemort will still worry that the prophecy will mean that Harry will end up destroying the world. So he will simply kill him anyway, like an AI Gatekeeper who doesn't listen but simply says "AI DESTROYED" immediately.

Voldemort knows that SOMEONE is prophesied to destroy the stars and be the end of the world. Harry is presently the best candidate by a large margin. By annihilating him, Voldemort loses all information about who's supposed to do this, and loses any assurance that whatever causes the fulfillment of the prophesy is something good.
I want to upvote this more than once. If you haven't posted to, then post this (with ‘Harry says:’ in front of it, I guess) before it's too late. People have come up with some good arguments as to why LV ought to let HPJEV live, but this one is the best.
You make a good point - in this instance, Voldemort is very much difficult to bargain with. However, I don't agree that that makes the problem impossible. For one thing, there may be solutions which don't require Voldemort's cooperation - e.g. silent transfiguration while stalling for time. For another, Harry can still get Voldemort's cooperation by convincing Voldemort that his current action is not in Voldemort's interests - for example, that killing Harry will actually bring about the end of the world that Voldemort fears.

Harry obviousely needs to buy some time, so he'd better start speaking. Patronus V2.0 grants only the "good" kind of power and feeds on caster's maxHP, so it could be revealed easier than partial transfiguration. Some meaningful amount of time is going to be acquired (while explaining HPJEV's viewpoint) that way, because HPJEV and LV oppose death in entirely different ways (one wants to fight it and the other one flees). But that's too easy and either is not in the solution at all or is followed but something more clever.

By the way, nobody said t... (read more)

The part that's going to really get to Hermione is the fact that someone (original Quirrell) was killed for her sake.
I thought it would be that she had received Dreadful in DADA. By LV himself, no less.
And that not-aging thing the regeneration ability grants her isn't necessarily going to be awesome either. What if her body decides to continuously regenerate into the form of her present-aged self?
Trolls do grow up, as previously notied. That's not the most likely way for that to be a problem. Rather the reverse. I mean, if troll regen runs off your genetic template, there is a good chance she is going to wake up as the prime-of-life (22?) adult version of herself, and continuously revert to that. I would even call it likely, except that from a meta perspective it would cause.. squicky.. reactions.
Point of pedantry, but we don't actually know that. It is possible that they spawn into existence full-grown as part of some magical process (fission, perhaps), or that their regenerative powers don't activate until they've grown to adult size. For the latter, it's not like they don't have enough other natural defenses to protect them until they reach adulthood.

Lets see..

Notes: EY didn't say that noone was aware of what was happening, just that anyone who would help Harry think he is at the game. Given the prophecy about Harry, this has disturbing implications.

Anyway: Obstacles: 39 minions in not-defensively enchanted blacks. One dark lord who can't use magic on you, but who can shoot your ass, An absolute prohibition on moves that could escalate to world threatening levels.

Assets: Naked pasty english lad. Wand. Parseltongue.

.. You know, normally in this sort of situation I'd recommend talking. Parselton... (read more)

Is it? Harry only took the vow moments ago--before that point, actions he was taking could have lead to the end of the world, and those action's consequences may still be in motion. The Vow only forces Harry to inaction if he knows he is at risk of causing the end of the world, as well. World ending may still be on the table.
Mostly I brought it up because people keep suggesting anti-matter. Anti matter could be mistaken for a nuclear weapon, which could escalate to WWIII, so the wow means he can't use it anymore. A pure light pulse wont set off those warning systems. Or at least, not at the level I'm thinking of.
A small antimatter explosion would not be mistaken for a nuclear weapon. In fact, a big antimatter explosion might be mistaken for a nuclear weapon, but since a missle would not have been detected, no-one would no who to retaliate against, and so retaliation would be delayed long enough for people to realise that there is no fallout and so it cannot be nuclear.
Nitpick - antimatter will also produce a pure light pulse, just the wavelengths are much shorter than the visible spectrum.
.. sigh the point is survival. A radiation pulse will hurt Harry the most, and will not be immediately obvious to people not fried by it. The idea is to disable opposition and summon help. In the event no help instantly materializes, dodge and start the incantation for fiendfire - it doesn't actually matter if you can't cast it. Everyone present will recognize it, and to a blinded wizard, fleeing should be utterly reflexive at that point.
Could he tell Voldemort aout partial transfiguration and request his own life spared?
Buffing the dark lord further is not an option. There is tonnes of things Harry could infer and then tell him that would make him delay. But this would be trading moments of life for further fucking over the world. Not a good trade.
He would tell he can do it, but not necessarily how it works. Of course knowing that problem is solvable facilitates solution, but since we know the solution, we also know it would take time for Voldemort to find and use it. So it is buffing, but with a time delay. That's why I think it's the simplest solution. Quirrelmort did start reading a book on physics, but is certainly far from understanding it deeply enough to do partial transfiguration. This move would simply buy Harry time. It won't solve the problem of Voldemort threatening the world, but will keep Harry alive, which is the objective of this quest. OK, then use that to buy Harry's own life. My idea was more about Harry buying his own life than telling about partial transfiguration.
Thing is, dying isn't the worst tactical option here. There is a chance buying the farm will just throw Harry into the horcruxi. Not certain enough to do it deliberately, but enough that any plan you come up with has to be better than the option of "Do nothing, die, hope to hang out in the horcruxi until Voldemort buys it again, let resonance remove you both from play" Which is a non-negligible bar to clear. Telling him a trick which might be the power he knows not to buy another minute of breathing doesn't pass muster. Telling him of the possibility doesn't pass muster. There are very few things which are both true and acceptable to tell Voldemort, simply because any information you give him, he will use against the world. If you give him information he can't use, he will ignore it.
He could certainly request it, but he won't get it.

I'm so confused about the wand. Why does Harry still have the wand? Obviously Voldemort should have demanded that Harry drop the wand before giving him 60 seconds to speak.

Maybe this is a test for Harry. V wants Harry to find a way to win.
Meta reasons? If Harry didn't have a wand this would be even harder. I agree this seems incompetent though, at least earlier he (may) have needed it for the Unbreakable Vow, which makes it less incompetent that him having had his wand unnecessarily for the last couple of chapters.

"You needed worthy opponentss,"

Harry can do a lot of things, but V already knows many of them. His strongest options are things he's sure V has no idea he can do, like the swerving hex he used on Moody.

EDIT: His strongest options for ways to outwit LV, not things to tell LV to save friends.

Considering QQ's disdain for dueling, I doubt LV would be interested in the Swerving Hex.
Which is amusing, and also means that it's the last thing he should tell LV. It is clearly a spell that is practically guaranteed to work against LV, since it could appear to miss only to swing back and hit either him or his shields. I would not be surprised in the slightest if it was essential to passing the test, given how perfectly it would work in this situation of magical resonance.

Let's discuss that mirror in a bit more detail. A fantastically powerful artifact that's trying to avoid the destruction of the world shouldn't be outside discussion when you (or Voldemort) are trying to avoid the destruction of the world.

First let's get away from suggestions like "Harry should convince Voldemort they're in the mirror". If Harry believed that were true, he wouldn't want to make Voldemort aware of it because Voldemort being trapped inside the mirror is good. If Harry believed they were not in the mirror, he couldn't claim he belie... (read more)

I have just realised that the 'partial transfigureation to create a steel monofilament' idea probably doesn't work. The problem is that in general, it doesn't actually require partial transfigureation - one could simply transform an object into a steel spike which pushes (rather than transfigures) its way through the soil, going under the shields and then up into your enemies' brain. If this worked, someone would have figured it out by now, because this requires no special knowledge. Therefore, there is some defensive shield which would prevent this attack, and presumably the Death Eaters have shields raised, unless they want to run the risk of a sudden attack wiping them all out at once.

I agree. Wizards would have caps on the ends of their wands for this sort of weapon if this were the case.
No one has been able to transfigure a piece of the air or ground before, as far as anyone knows, so the shields might not be designed to block that. Transfigured tendrils that intersect all the bad guys' spinal cords at the neck level would do the trick. Only question is if Harry has the range to do that.
No, I mean transfigure a steel spike that pierces through the ground, without actually being transfigured from the ground.
Would would Harry not transfigure it from the ground? Or the air from that matter? What else does he have to work with? And he'd be transfiguring part of their bodies too. Wouldn't work on Voldie due to resonance cascade, but he could disable the uzi.
I mean that transfigureing a steel spike through the ground is doable without partial transfigureation, so it would have been tried before and would be used as a battle tactic already if it worked.
Wouldn't you need partial transfiguration to make the spike out of a piece of earth? Regardless, that's not what I'm proposing that Harry should do. I'm saying he should use partial transfiguration to make acid or cesium threads through the air that include the death eaters and Voldemort's handgun in the transfigured material. That has never been done before, and its likely there won't be defenses against it.
No, I mean you transfigure something else into a spike, and the transfiguration pushes the material through the ground. Sheilds stop projectile weaponry (up to a point) and I'm not sure this is any different.
It wouldn't be a projectile. It would be transfiguring part of the enemy INTO acid or some other deadly substance by including a bit of their body inside of Harry's conceptual "object."

Thinking about AI boxing - note that it is Harry who represents humanity, his core values and goals were not changed that much by the Vow, they were just formalized.

It is LV that has goals that are mostly what we'd agree about (`ensure the continuous existence of the world'), but he has very different values and no moral constraints. In short, dealing with him is like dealing with an Unfriendly AI or an Alien mind (like Sorting Hat).

So this is more like a clash between Unfriendly (or better, Indifferent) and a Friendly AI, where the goals are more or less... (read more)

Same thing. ‘The AI does not hate you, nor does it love you, but you are made out of atoms which it can use for something else.’

Here is a suggestion that I haven't seen yet. I don't think it constitutes a full plan by itself, but it fits the form of an AI box experiment with Harry as the AI.

Harry and Voldemort's discussion about testing his horcrux 2.0 spell by offering immortality to one of his friends (read: minions, in his case) revealed a weakness, that Voldemort is heavily biased against certain ways of thinking. Harry should remind him of this in the context of the Patronus 2.0 spell. The fact that Harry was able to discover a new (and incredibly powerful, as we have seen) fo... (read more)

Regardless of other differences in utility function, Harry and Voldemort both want the world to not be destroyed, and consider this of the utmost priority.

Aumann's agreement theorem means that as they are both rationalists, they should be able to come to the same opinion on what the best course of action is to prevent that. Harry was willing to sacrifice himself earlier to save others.

The case for thinking seriously about Partial Transfiguration:

1) Partial transfiguration is wordless, but wanded.

2) it's a power Riddle doesn't know as per the prophecy.

3) Harry still holding his wand is a Chekov's Gun for a wanded spell such as transfiguration.

4) Yes, that does seems too obvious, but I don't think Eliezer wants to end the story here so he wouldn't want an extremely subtle puzzle.

5) The only evidence against is that Quirrell might have ripped it from Hermione's mind...but he wouldn't know what to look for, would he? And Dumbledore may w... (read more)

I'm not too sure about your #4, but #2 definitely cannot be counted upon to be true. In Chapter 92, in a conversation between McG and LV: It has been pointed out that if LV discarded treating this as a game, which does appear to be the case, then he may well have been using Legilimency on McG, in which case he would know of it, at least. Which isn't to say that we couldn't use it to bargain for the lives of others, or whatnot. But you can't trust that it's still unknown to LV. Furthermore, have we seen Harry transfigure the air? I remember him speculating that he could, trying, and failing. I don't remember him succeeding at a different time.
One of the transfiguration safety rules: Never transfigure something into anything that might be eaten or breathed. Is it possible to demonstrate partial transfiguration (on, for example, his father's rock) while transforming much of its substance very temporarily into a breathable gas?
I think those are just safety rules, rather than laws of transfiguration magic, so it should be possible. (in any case, I don't really think partial transfiguration is actually the solution, since anything which involves combat is necessarily a long shot with too many magical unknown unknowns to count).
Immediate Idea #1: Take deep breath. Transform tiny piece of ground into a gas. Start explaining secret in parseltongue, do not inhale. Voldemort inhales some of the gas, causing magical resonance. Voldemort hopefully dis-corporates. Harry and death eaters comes down with probably curable transfiguration sickness, Harry less so for not having inhaled. Harry still dies because the death eater's fire on him, so this idea fails :( Still, in Harry's place, with as much time to think as Harry has had, this is what I would do. (Followed by casting the patronus charm ASAP to block the incoming barrage of AK, ducking, Bubblehead charm, and massive, lethal-to-anyone-that-breathes transfigurations. It's probably too much to hope that at least one death eater was a spy, but that would also help. It sucks that Harry can't Apparate.)


  • Can the unbreakable vow be leveraged for unbreakable pre commitments?
  • Harry knows that the horcruxes will eventually be destroyed through heat death of the universe if nothing else and could use this to tell Voldemort something like "if you kill me you will die" in parseltongue
Isn't this its only use?
I mean the existing unbreakable vow that Harry has just been bound by could perhaps be used for something else.

Also,question. Do our suggestions need to be posted on, or does this thread count?


I remembered I have a PredictionBook account that I registered some years ago and forgot about, so I might as well get started with this whole "calibration" business.

The true solution will hinge on truly convincing Voldemort to let Harry out of the box (i.e. no “brute force” transfiguration solutions where talking is just a distraction): 95%

The true solution involves time travel: 50%

The true solution relies on Partial Transfiguration: 80% (this isn't in contradiction with #1 - it can involve Partial Transfiguration (e.g. as a threat, or a demonst... (read more)

Working backwards is a standard strategy for solving puzzles like this. Let's imagine Harry having gotten out of the predicament. How does the situation look? Where is Harry? Where is Voldemort? Where is Hermione?

Edit: TL;DR I made equivalent problem. It is sufficient and necessary. Prove: p(H causes destruction | H is Alive) < p(H causes destruction | H is Dead)

I have exams so I don't have enough time to do the whole process, as it should be done. I wanted to donate my thoughts and hope for someone else to do the job.

If you remember, we are not supposed to give solutions at once, we should talk about problem first. This includes gathering fair knowledge about all the mechanisms mentioned.

I see some people listed available objects, which could be used in open c... (read more)

Did i fail in my reasoning here? Because if i didn't, it is of major importance, and if i did, well, it's not important at all, but i would still like to know where i failed. On the other hand, I see people have been trying to isolate themselves, so, i suppose my comment got unnoticed because of that.

Random lines of thought to explore:

Can we figure out how sacrificial magic works from available evidence(we've seen a lot of it recently) and could Harry use that new knowledge to solve his predicament? A principle similar to the potion making principle perhaps?

Harry had to go all the way down to timeless physics in order to do partial transfiguration. I know very little about the theory but could Harry apply that knowledge to somehow partially transfigure time itself or transfigure something not in his present?

If Harry can convince Voldemort to allow him... (read more)

ROT 13ed Final Exam suggestion:

Va Cnefyrgbathr "Jung cebonovyvgl qb lbh nffvta gb gur cbffvovyvgl gung V nz fhssvpvragyl Gbz Evqqyr gung V jvyy or pbcvrq vagb lbhe Ubepehk argjbex?"

Re-reading the story, this made me smirk in light of recent revelations:

Harry scowled at her. "Fine, I won't bite anyone who doesn't bite me first."

Harry should trick Voldemort into biting him, and then use his new freedom to bite him back.

It occurs to me that, given the philosopher's stone is around, any superweapons Harry could create and conceal with it in slightly under an hour could exist in the clearing, provided that they're enough to let Harry survive another hour, access the time turner, and create said superweapons.

Also, since prophecies are self-fulfilling and Voldemort prefers a world that won't end to a world that will and Harry has already made the appropriate unbreakable vow to do everything to prevent the end of the world, Harry could argue that expected universe where Voldemort lets Harry live is far superior to the one where Harry dies.

"Expecto Patronum", at which point Death-Eaters will fire an utterly futile barrage of AKs. Voldy still can't fire directly at Harry due to resonance. Gun is not as much concern if you move fast enough and considering Voldy is some distance away. Gives Harry enough elbow room to get to his nearby (?) Pouch, Cloak and Time-Turner with 1 more hour on it. At this point we're sorta free of any serious constraints.

So the Patronum is between Harry and each and every one of the death eaters? That seems dubious, unless he's wearing it like a suit. Also, they been instructed to use different attacks, so unless the Patronus blocks everything I don't think it'd stop everything that would come his way.
Wearing the Patronus isn't any more dubious than casting it inside of Hermione to revive her. You're right about stunners instead of AKs of course, but that can be blocked by a thin invisible tranfigured shield (air into glass, since apparently he can transfigure arbitrary atomic structures). Transfiguration is wordless and he has a wand. I mean, this isn't anywhere near as deus-ex-machina as half of the Azkaban escape anyway.
Read a comment above; he cannot transfigure air.
That was prior to PT.
You're right, I should have read more comments myself.
Read a comment above; he can cast the Patronus in the shape of a sphere.

This is very similar to a solution I published earlier, except that when I first proposed it, I had forgotten that Harry hadn't got his wand at that point in time (but why hasn't he been disarmed now?).

The one plausible power Harry has is transfiguration, seeing as there are no dementors nearby, it seems unlikely that the patronus 2 can be used as an offensive weapon against anything apart from dementors.

Harry should transfigure some exotic matter with density far in excess of normal matter, and use it to slice through all the death eaters and Voldiemort. ... (read more)

Weapon: 37 ants.
It can? I don't remember that. But if true, can it be willed to take the form of a sphere around Harry, thereby providing a perfect anti-Killing Curse shield?
The patronus is willed to take the form of a sphere when Harry leads the Aurors to rescue Draco. And, yes, it might protect from AKs and from Voldie, but the Death Eaters have been instructed to attack Harry with a wide variety of curses.
Not going to stop Fiendfyre, or any of a hundred other things Voldy can do to kill him.
No, the resonance effect will take care of that. Voldemort's only viable means of killing him immediately and directly is the gun.
That is very unlikely.
He's a competent antagonist.
He is. But assuming that he is super-prepared, beyond the abilities and equipment we've seen or been given reason to postulate, results in an unsolvable puzzle. Someone as intelligent, experienced, prepared and resourceful as Voldemort could theoretically have a counter for anything we can come up with. We know or can reasonably assume that he obtained a gun specifically as a solution to the problem of not being able to injure or kill Harry with magic. We don't have any reason to believe that he has prepared further, backup solutions to that specific problem.
There's one thing for which it's genuinely impossible for V to have a counter: the realization that killing Harry is not in his interests. Speaking in Parseltongue, bound by the Vow, Harry is uniquely prepared to make that case -- assuming it's true.
Well, that's the sticking point. Parseltongue and the Vow prove that Harry is honest. They don't prove that he's right, and Voldemort can simply choose to dismiss any of Harry's arguments as insufficient (which isn't that hard, given that the risk of keeping him alive is the end of the world, and any risk incurred by killing him is probably going to be less bad).
Or having a Death Eater do it for him.

Here's another object-level tactic I haven't seen mentioned yet. (Assume LV will not just kill Harry for speaking of non-magical powers. I have a way of increasing the likelihood of this assumption being true)

Harry could explain the Power of Expected Utility Calculations and subtly attempt a Pascal's Mugging on LV, convincing him that LV can't possibly assign a probability of less than one in twenty that killing Harry will indeed avert the prophecy, or for that matter cause it, and that the rational action to take is to not kill Harry. He can present it as... (read more)

Yeah, this is basically the route I'd do. Except I added one more ingredient. Here, I'll just quote my review.
Nice. I like it. I expanded my previous post in a full solution (very long) with a pretty thorough line of reasoning. In the end, I convinced myself that Voldemort is not acting in his self-interest by killing Harry and that he's dangerously overconfident in his understanding of the Prophecy and his ability to avert it. Here are the relevant excerpts from my solution:
Also can not assign less than 1/20 probability that keeping him alive will destroy the world. So...?
This is new as far as I can tell. Please write up a review based around this, and based on a cursory read through of Reddit, it might be best not to do this in prose, it takes even longer to evaluate apparently and Eliezer's plan has backfired (look at last entry in "Fan Works" tab)
I submitted it. Here's the link to my whole solution (It's long, with backup plans and a few unique mechanics) if you're interested. I'm pretty proud of it, given the time constraints.

Ssome livess I have already promissed you, but otherss I did not. . . For each unknown power you tell me how to masster, or other ssecret you tell me that I desire to know, you may name one more of thosse to insstead be protected and honored under my reign. Thiss alsso I promisse and intend to keep.

Is Harry permitted to name himself as a person to be protected? It doesn't seem to say that he cannot. I believe partial transfiguration would buy him a life. It's an unsatisfying solution, as it only saves Harry. But then again, the exam only requires Harry to survive.

He's not permitted. LV said "name one or more of those", where those refers to the people he named in the previous sentence, i.e. Harry's parents and his "mudblood friends" in the armies.
Surely other lives are permitted though, such as Neville. Voldemort said specifically: "Your mudblood servants in your little army. Your precious parents." That would exclude Neville (who isn't muggle-born) and Cedric (who isn't in Harry's army).

Transfiguration requires the caster's wand to touch the target. However, Harry's understanding of partial transfiguration was based on his understanding of the underlying quantum field nature of reality. This means that Harry's wand is touching everything all at once. He should be able to Transfigure anything in the area that he wants, and based on the Azkaban sequence, he could think or speak while doing so.

Make sure you post this in a review, even if it doesn't end up being directly relevant to the solution you post. And mention that this fact should be considered in the judging of everyone else's solutions.

I have read several reviews on, and posts here, that say Harry will transfigure a very thin knife out of the tip of his wand and cut off all the Death Eaters' heads, perhaps while distracting Voldemort with words. While that could happen, I think it would be better for Harry to go for their arms. No arm means no mark, and no pointing wands, but is much easier to survive, especially with magic medicine and the Philosopher's Stone right there!. Actually, Harry could transmute enough phosphorus to burn so bright as to blind everyone behind him ... (read more)

This would most likely require the Philosopher’s Stone to be in contact with the transfigured matter for several minutes (see chapter 111), which is impossible: (chapter 15; emphasis mine)
The correct way to solve the problem is to apply another Transfiguration to turn the victim's body into its healthy form, then use the Philosopher's Stone to make the second Transfiguration permanent. Is there a reason why this would not work?

This solution does not prevent Harry's immediate death, but seems much better than that to me anyway. I haven't been following conversations before, so I can only hope that this is at least somewhat original.


-Lord Voldemort desires true immortality. Alternatively, there is a non-zero chance that he will come to desire true immortality after a long time of being alive. While he is a sociopath and enjoys killing, achieving immortality is more important to him.

-Lord Voldemort does not dismiss things like the Simulation Hypothesis out of hand. Sinc... (read more)

I am actually reluctant to think of ways for HP to escape, because I am kind of rooting for LV in this fic. Sure, he is ruthless and stuff, but he seems to be way less dangerous than Harry, who is prophesied to destroy the world. LV just hates stupid people. Plus he has all but made Hermione immortal, and she the only voice of reason in the story. And he likes gazing at stars, and is against nuclear weapons. A competent ruler is such a rarity. As kings go, he would be considered cute.

Didn't V see at least the results of a Partial Transfiguration in Azkaban (used to cut through the wall)? Doesn't seem like something V would just ignore or forget.

I believe Voldemort was unconscious at the time, following a magical feedback mishap at the conclusion of his duel with Bahry. Bellatrix was awake, but probably not very coherent after eleven years in Azkaban, and Voldemort strikes me as the type to dismiss confusing reports from unreliable underlings.
Chapter 58 I'm kind of worried about this... all the real attempted solutions I've seen use partial transfiguration. But if we take "the antagonist is smart" seriously, and given the precedent for V remembering and connecting obscure things (e.g. the Resurrection Stone), we should assume V has protections against that tactic. It is not a power the Dark Lord knows not. And come to think of it, V also saw Harry cutting trees down with partial transfiguration.

Voldemort might be failing to anticipate partial Transfiguration that has no visible effects (although it's unclear why Harry is allowed to hold the wand after the Vow is done). It might be Transfiguration of the tip of the wand or of a patch of own skin. Transfiguring it into carbon nanotube wires (Ch. 28) or something else super thin that's good at cutting things might make the result both deadly and invisible, while keeping the amount of stuff small in order to be able to complete the process in reasonable time (as with cutting the wall in Azkaban, Ch. ... (read more)

Harry can also dispel any of his transfiguration wandlessly and wordlessly. So any toxic substance he creates he can dispel as it reaches him.

But it does not serve as a solution to say, for example, "Harry should persuade Voldemort to let him out of the box" if you can't yourself figure out how.

It's a shame that nobody's going along this line of thought. It would be cool to see a full, successful AI-Box experiment out there as a fanfiction.

(I'd do it myself, but my previous attempts at such have been.... eheh. Less than successful.)

Actually, this isn't anywhere near as hard as the AI Box problem. Harry can honestly say he is the best option for eliminating the unfriendly AGI / Atlantis problem. 1) Harry just swore the oath that binds him, 2) Harry understands modern science and its associated risks, 3) Harry is 'good', 4) technological advancement will certainly result in either AGI or the Atlantis problem (probably sooner than later), and 5) Voldemort is already worried about prophecy immutability so killing Harry at this stage means the stars still get ripped apart, but without all the ways in which that could happen with Harry making the result 'good').
Other than (5), these are all things that are liable to be true of an AI asking to be let out of the box. 1. Code that appears Friendly but has not been proved Friendly 2. Advanced intelligence of the AI 3. General programming goals, much weaker than (1) really 4. True verbatim in the standard AI box experiment (and arguably in the real world right now)
I see your point, but Voldemort hasn't encountered the AI Box problem has he? Further, I don't think Voldemort has encountered a problem where he's arguing with someone/something he knows is far smarter than himself. He still believes Harry isn't as smart yet.
Sure, but now your argument, it seems to me, is 6) Harry is playing against the intelligent but naïve Voldemort instead of against the intelligent and experienced Nathan Russell. (Actually, I don't know who Russell is apart from being the first person to let EY out of the box, but he may well be experienced with this problem, for all I know, and he's probably intelligent if he got into this stuff at all.)
LV clearly doesn't want the world to end. What would make him believe that killing HP ends the world?

I think a big question here is "what kinds of magic, if any, are available?". Answer might be "none". Partial transfig takes too long, everything else requires motion.

That seems to leave to possibilities:

  • Realizations that allow for re-access to magic
  • Talking your way out of it

In other words, no known magic is useful in this situation.

Does that seem reasonable? Does anyone remember a form of magic that doesn't require motion or time?

He learned that he can will his own transfigurations to end wandlessly and without spoken words.
So, release of magic doesn't require movement. That's something.

"Having made the Unbreakable Vow, it is impossible for me to engage in motivated reasoning which would put the world at risk, while it is entirely possible for you to do so. I am convinced that you are more likely to fulfill the prophecy by killing me than by letting me live. Since my reasoning is not and cannot be motivated in such a way as to put the world at risk, while yours can be, it is more likely that I am right, and it would be to your advantage not to kill me."

Also, if Harry finds it impossible to say this in Parseltongue, then he will simply agree to die, since it will be safer for the world.


This is a two step solution. The first part succeeds or fails deterministically. If the first part fails the fallback comes into play and that succeeds or fails probabilistically, so you may need to generate a pseudo random number to evaluate this proposal.

Part 1: this part uses partial transfiguration and his newly practiced skills from the 6th year textbook.

Harry must transfigure something touching his wand, so the object transfigured is a small patch of skin touching his wand. He will probably lose that bit of skin when the transfiguration wear... (read more)

At least one other person has suggested stating plainly, in Parseltongue, that the optimal way to kill Harry would be to send him to Azkaban and let him kill the dementors. If that doesn't kill him, then continue with the previous plan. I doubt this is in fact the safest way to dispose of Harry, but it might be possible as an extra idea to gain time.

I make the following prediction : the transfiguration exercise of ch. 104 foreshadows the possibility of safely transfiguring a certain kind of explosive, that relies on containing several components that will explode upon contact. The ch. 104 exercise tells us that containment chambers can be formed first, and their contents afterwards, such that the bomb will not accidentally explode during transfiguration.

Voldemort has promised in Parseltongue:

"For each unknown power you tell me how to masster, or other ssecret you tell me that I desire to know, you may name one more of thosse to insstead be protected and honored under my reign."

1) If Harry was able to give Voldemort an infinite number of powers, through the use of recursion or some mathematical trick or something - some way that Magic Itself will consider to be a large/infinite number of separate but related powers, and

2) If Harry was able to enunciate in some way an infinite number of being... (read more)

Parseltongue isn't Unbreakable Vow, it doesn't prevent people from changing their mind. Any attempt from Harry to abuse the promise like that will probably make Voldemort reconsider and no longer allow to name new persons for the same "class" of powers (like, early in the year, he said things like "no more body parts" when Harry was enumerating lots of body parts he could use to kill someone).
Statements in Parseltongue aren't binding vows, they're just honest statements of intention.
Yes I agree. There needs to be another Magical effect which causes Voldemort's parseltongue statements to become binding in some way.
Are you asking for suggestions???

Can people who have posted their solutions to FFN state as much in their comments so we don't have to wade through the FFN reviews?

Harry is allowed to convince voldy to keep him in a coma to kill later. He just has to "evade immediate death", even if there is no hope of survival afterwards

Yes, but given that he might be tied to the horcrux network, that is strictly a more dire defeat than just letting Voldemort kill him. There is a chance his demise will poison the horcruxi for Voldemort - if they are both in there, that should obviously set of the resonance, and that is the end of the dark lord. This is useless as a strategy because if it works at all, it is what will happen if he just does nothing, But bringing it to Voldemort's attention is a loosing move. I spent a fair bit of time thinking of things to tell Voldemort to get him to stop, but every single idea I came up with had very similar problems to that one - The only things likely to hold his attention are things that make him more of a danger to the world, or threats to his continued existence he should remain ignorant of. Hence the lightbomb. Then either bluff that he is casting fiend-fire or deliberately trigger the resonance.

Challenge accepted.

I've already got the seed of a solution which I'll be fleshing out and posting formally, later.

(And it took me half an hour after coming up with it, to get here, register, and figure out how to post.)

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Solution submitted. Thus far, this thread does not include mention of what I would consider to be Harry's greatest weapon. He hasn't just been practicing "partial transfiguration". He's been successfully practicing discarding any notion of time, space, object or causality, in toto. To clarify: if you do away with time, you also radically change the meaning of space. It's all just wave equations. I can't bold that big enough.
Note that to save the story you need to post at fan fiction as a review, not just here

A transfigured port key in his glasses does seem possible, or some kind of explosive device hidden in the transfigured ring.

EDIT: Fawkes is also a way out here, if Harry can delay an enemy attack for several seconds

Second edit (the serious one): The ring contains some kind of binding device. This could be the blinding potion Harry used in battles, a set of flash-bang grenades, or (most likely) a seventh-year variant of the blinding potion Harry bought off a student. This countermeasure will blind the unwarded death eaters which allows Harry to immediately fall to the ground and call Fawkes. Fawkes teleports Harry out and allows escape.

I was wondering how much retroactive power we would have. Harry would know, or be able to look up, any number of chemicals that would react very poorly to the open air. It would be exceedingly foolish to carry one on his person, transfigured, such that he would simply have to negate the tranfiguration to have a distraction or attack, but would such a thing be in our power to suggest into existence, if we thought of a sufficiently non-foolish way for Harry to carry this?
I was thinking of a transfigured portkey attached to one of his fingernails. That way even if bound he should still be able to activate it.
BUT The students were issued with portkeys in the form of toe rings and Harry got rid of his explicitly.


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V's giving his gun to one of his followers (who are blood purists, not muggle technology experts, and probably haven't ever fired a gun) suggests that he is still unable to "raise hand or wand against" Harry, for whatever reason.

If Harry can cause himself to appear to be V, the Death Eaters will presumably be confused enough to give him time to act (given that V cannot disable Harry himself). Harry can then use magical resonance to cause V to turn into a snake and/or explode, convincing the Death Eaters that he is really V.

The hole in this plan i... (read more)

Not that he isn't able but that there might be some protection Harry uses. It's less risk to give the gun to someone else.

Might get around to posting a solution. Here's the direction I'm headed:

I think I have a reasonable timetable that can be found in this post. I figure there's at most an hour and a half left until Harry leaves the Quiddich game. I don't expect the cavalry to save the day, but it imposes a time restriction.

Cedric is a wild card here. If he were to accompany Harry then we probably would have learned of it by now. Otherwise, he may have been asked to raise the alarm should Harry fail to return in a timely manner, so I think it's safe to suppose that the time... (read more)

Do note that Voldemort cannot actually use Legilimency on Harry, due to magical resonance. Not only would this be expected due to how the effect has manifested in the past, but EY has also confirmed that this was the original reason for the resonance in the first place. It could be possible for a Death Eater to do so in his stead, but I do not think it at all likely without further orders from Voldemort, given his explicit desire for privacy in their conversation. Regarding Dumbledore's decision, it could simply be that (due to the prophesy) he believed Harry the only one who could defeat Voldemort, and so the loss of Harry would mean that his own presence would be useless in that regard. Better a minuscule chance of saving the world than none at all.
I may be misinterpreting, but I thought the whole resonance business got cleared up when Voldemort lured Harry into shooting at him.
I might be wrong, but I interpreted that as Tom having made a previous commitment to not raise had nor wand against other versions of himself. That curse is gone, but the resonance is a distinct entity and is still there.
Addendum: being as Voldemort hadn't done much testing on his Horcrux network and Harry is Tom Riddle, it may be possible for Harry to die and still be able to return using said Horcrux network.

There are all sorts of ways to fight using partial transfiguration. Many of the obvious ones mentioned so far are too slow (tunneling through the ground, nerve gas), suicidal (micro black holes, antimatter, unununium, critical mass of enriched uranium, nitroglycerin, etc.) or too complicated.

only a fool would attempt a plot that was as complicated as possible, the real limit was two.

On the other hand, Dumbledore took the shotgun approach to plotting. Let's take the best of both worlds.

Then the obvious answer is chain lightning! Transfigure the air into... (read more)