Diplomacy as a Game Theory Laboratory

by Scott Alexander12 min read12th Nov 201098 comments

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Gaming (videogames/tabletop)Game Theory
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Game theory. You've studied the posts, you've laughed at the comics, you've heard the music1. But the best way to make it Truly Part Of You is to play a genuine game, and I have yet to find any more effective than Diplomacy.

 

Diplomacy is a board game for seven people played on a map of WWI Europe. The goal is to capture as many strategic provinces ("supply centers") as possible; eighteen are needed to win. But each player's country starts off with the same sized army, and there is no luck or opportunity for especially clever tactics. The most common way to defeat an enemy is to form coalitions with other players. But your enemies will also be trying to form coalitions, and the most profitable move is often to be a "double agent", stringing both countries along as long as you can. All game moves are written in secret and revealed at the same time and there are no enforcement mechanisms, so alliances, despite their central importance, aren't always worth the paper they're printed on.

 

The conditions of Diplomacy - competition for scarce resources, rational self-interested actors, importance of coalitions, lack of external enforcement mechanisms - mirror the conditions of game theoretic situations like the Prisoner's Dilemma (and the conditions of most of human evolution!) and so make a surprisingly powerful laboratory for analyzing concepts like trust, friendship, government, and even religion.

 

Over the past few months, I've played two online games of Diplomacy. One I won through a particularly interesting method; the other I lost quite badly, but with an unusual consolation. This post is based on notes I took during the games about relevant game theoretic situations. You don't need to know the rules of Diplomacy to understand the post, but if you want a look you can find them here.

 

Study One: The Prisoner's Dilemma


The Prisoner's Dilemma is a classic case in game theory in which two players must decide whether or not to cooperate for a common goal. If both players cooperate, they both do better than if both defect, but one player can win big by defecting when the other cooperates. This situation is at the heart of Diplomacy.

 

Germany and France have agreed to ally against Britain. Both countries have demilitarized their mutual border, and are concentrating all of their forces to the north, where they take province after province of British territory.

 

But Britain is fighting back; not successfully, but every inch of territory is hard-won. France is doing well for itself and has captured a few British cities, but it could be doing better. The French player thinks to eirself: I could either continue battering against the heavily defended British lines, or I could secretly ally with Britain, stab Germany in the back, and waltz in along our undefended mutual border before the Germans even know what hit them. Instead of fighting for each inch of British land, I could be having dinner in Berlin within a week.

 

Meanwhile, in Berlin, the German player is looking towards France's temptingly undefended border and thinking the exact same thing.

 

If both France and Germany are honorable, and if both countries know the other is honorable, the two of them can continue fighting Britain with a two-to-one numerical advantage and probably divide England's lucrative territory among the two of them.

 

If Germany is naively trusting and France is a dishonest backstabber, then France can get obscene rewards by rolling over Germany while the Kaiser's armies are tied up on the fields of England.

 

If both countries are suspicious of the other, or if both countries try to backstab each other simultaneously, then they will both divert forces away from the war on England to guard their mutual border. They will not gain any territory in England, and they will not gain any territory along their border. They've not only stabbed each other in the back, they've shot themselves in the foot.

 

Study Two: Parfit's Hitch-Hiker


The wiki describes Derek Parfit's famous hitchhiker problem as:

 

Suppose you're out in the desert, running out of water, and soon to die - when someone in a motor vehicle drives up next to you. Furthermore, the driver of the motor vehicle is a perfectly selfish ideal game-theoretic agent, and even further, so are you; and what's more, the driver is Paul Ekman, who's really, really good at reading facial microexpressions. The driver says, "Well, I'll convey you to town if it's in my interest to do so - so will you give me $100 from an ATM when we reach town?"

 

Now of course you wish you could answer "Yes", but as an ideal game theorist yourself, you realize that, once you actually reachtown, you'll have no further motive to pay off the driver. "Yes," you say. "You're lying," says the driver, and drives off leaving you to die.

 

The so-called Key Lepanto opening is one of the more interesting opening strategies in Diplomacy, and one that requires guts of steel to pull off. It goes like this: Italy and Austria decide to ally against Turkey. This is common enough, and hindered by the fact that Turkey is probably expecting it and Italy's kind of far away from Turkey anyway.

 

So Italy and Austria do something unexpected. Italy swears loudly and publicly that ey's allied with Austria. Then, the first turn, Italy moves deep into undefended Austrian territory! Austria is incensed, and curses loud and long at Italy's betrayal and at eir own stupidity for leaving the frontier unguarded. Turkey laughs and leaves the two of them to their war when - boom - Austria and Italy launch a coordinated attack against Turkey from Italy's base deep in Austrian territory. The confused Turkey has no chance to organize a resistance before combined Italo-Austrian forces take Constantinople.

 

It's frequently a successful strategy, especially for Italy. You know what else is a successful strategy for Italy? Doing this up to the point where they take over lots of Austrian territory, forgetting the part where it was all just a ploy, and then ending up in control of lots of Austrian territory, after which they can fight Turkey at their leisure.

 

It's very much in Italy's advantage to play a Key Lepanto opening, and they may beg the Austrian player to go for it, saying correctly that it would benefit both of them. But the Austrian player very often refuses, telling Italy that ey would have no incentive not to just keep the conquered territory.

 

This problem resembles the Hitchhiker: Italy is the lost man, and Austria is the driver. Italy really wants Austria to help em play the awesome Key Lepanto opening, but Austria knows that ey would have no incentive not to break his promise once Austria's given him the help he needs. As a result, neither country gets what they want. The Key Lepanto opening is played only rarely, and this is one of the reasons.

 

Study Three: Enforceable Side Contracts


The Prisoner's Dilemma is nontrivial because there's no enforcement mechanism. In the presence of an enforcement mechanism, it becomes much simpler. Say two mobsters are about to be arrested, and expect to be put in a Prisoner's Dilemma type situation. They approach the mob boss with a contract with both of their names on it, saying that they have both agreed that if either of them testifies against the other, the mob boss should send his goons to shoot the rat.

 

For many payoff matrices, signing this contract will be a no-brainer. It ensures your opponent will cooperate at the relatively low cost of forcing you to cooperate yourself, and almost guarantees you safe passage into the desirable (C,C) square. Not only does it prevent your opponent doesn't defect out of sheer greed, but it prevents your opponent from worrying that you're going to defect and then defecting emself to save emself from being the chump.

 

The game of Diplomacy I won, I won through an enforceable side contract (which lost me a friend and got me some accusations of cheating, but this is par for the course for a good Diplomacy game). I was Britain; my friend H was France. H and I knew each other from an medieval times role-playing game, in which we both held land and money. The medieval kingdom of this game had a law on the books that any oath witnessed by a noble was binding on both parties and would be enforced by the king. So H and I went into our role-playing game and swore an oath before a cooperative noble, declaring that we would both aid each other in a permanent alliance in Diplomacy, or else all our in-game lands and titles would be forfeit.

 

A lot of people made fun of me for this, including H, but in my defense I did end up winning the game. H and I were able to do things that would otherwise have been impossible; for example, in order to convince our enemy Germany that we were at war, I took over the French city of Brest. Normally, this would be almost impossible for two allies to coordinate, even as a red herring, for exactly the reasons listed in the Hitchhiker problem above. Since the two of us were able to trust each other absolutely, this otherwise difficult maneuver became easy.

 

One of the advantages to strong central government is that it provides an enforcement mechanism for contracts, which benefits all parties.

 

Study Four: Religion As Enforcement


Religion is a special case of the enforceable side-contract in which God is doing the enforcing. God doesn't have to exist for this to work; as long as at least one party believes He does, the threat of punishment will be credible. The advantage of being able to easily make enforceable side contracts even in the absence of social authority may be one reason religion became so popular, and if humans do turn out to have a genetic tendency toward belief, the side contracts might have provided part of the survival advantage that spread the gene.

 

In a Youngstown Variant game (like Diplomacy, but with Eurasia instead of just Europe), I was playing Italy and after colonizing Africa was trying to juggle my forces around to defend borders with Germany, France, Turkey, and India.

 

India was played by my friend A, who I sometimes have philosophical discussions with and who I knew to be an arch-conservative religion-and-family-values type. I decided to try something which, as far as I know, no one's ever tried in a Diplomacy game before. "Do you swear in the name of God and your sacred honor that you won't attack me?" I asked.

 

"Yes," said A, and I knew he meant it, because he takes that sort of thing really seriously. I don't know if he thought he would literally go to Hell if he broke his oath, but I'm pretty sure he wasn't willing to risk it over a board game. So I demilitarized my border with India. I concentrated my forces to the west, he concentrated them to the east, and both avoided a costly stalemate in the Indian Ocean and had more forces to send elsewhere. In the future, I will seek out A for alliances more often, since I have extra reason to believe he won't betray me; this will put A in an unusually strong position.

 

This is not a unique advantage of religion; any strongly held philosophy that trumps self-interest would do. I would have made the same deal with Alicorn, who has stated loudly and publicly that she is a deontologist who has a deep personal aversion to lying2. I would have made it with Eliezer, who has a consequentialist morality but, on account of the consequences, has said he would not break an oath even for the sake of saving the world.

 

But I only trust Alicorn and Eliezer because I've discussed morality with both of them in a situation where they had no incentive to lie; it was only in the very unusual conditions of Less Wrong that they could send such a signal believably. Religion is a much easier signal to send and receive without being a moral philosopher.

 

Study Five: Excuses as Deviations from a Rule


My previous post, Eight Short Studies on Excuses, was inspired by a maneuver I pulled during a Diplomacy game.

 

I was Italy, and Turkey and I had formed a mutual alliance against Austria. As part of the alliance, we had decided not to fight over who got the lucrative neutral territories in between our empires. I would get Egypt, Turkey would get Greece and Yemen, and we would avoid the resource drain of fighting each other for them so we could both concentrate on Austria.

 

Both Turkey and I would have liked to grab the centers that had been promised to the other. But both Turkey and I knew that maintaining the general rule of alliance between us was higher utility than getting one extra territory. BUT both Turkey and I knew that the other would be loathe to break off the alliance between just because their partner had committed one little infraction. BUT both Turkey and I knew that we would have to do exactly that, or else our ally would have a carte blanche to violate whatever terms of the alliance they wanted.

 

Then India (from whom I had not yet extracted his oath) made a move towards Yemen, threatening to take it from both of us. I responded by moving a navy to Yemen, supposedly to see off the Indian menace. I then messaged Turkey, saying that although I still respected the terms of our alliance, he was clearly too weak to keep Yemen out of Indian hands, so I would be fortifying it for him, and I hoped he would have the maturity to see this as a mutually beneficial move to prevent Indian expansionism, and not get too hung up on the exact terms of our alliance.

 

The gambit worked: Turkey decided that maintaining our alliance was more important than keeping Yemen, and that because of the trouble with India my conquest of Yemen was not indicative of a general pattern of alliance-breaking that needed to be punished.

 

I can't claim total victory here: several years later, when the threat of Austria had disappeared, Turkey betrayed me and captured half my empire, partly because of my actions in Yemen.

 

Study Six: For the Sake of Revenge


This comes from the book Game Theory at Work:

 

Consider the emotion of revenge. At its core, revenge means hurting someone who has harmed you, even if you would be better off leaving him alone. Revenge is an irrational desire to harm others who have injured our loved ones or us.

 

To see the benefit of being known as vengeful, consider a small community living in prehistoric times. Imagine that a group of raiders stole food from this community. A rational community would hunt down the raiders only if the cost of doing so was not too high. A vengence-endowed community would hunt down the raiders regardless of the cost. Since the raiders would rather go after the rational community, being perceived as vengeful provides you with protection and therefore confers an evolutionary advantage.

 

I play Diplomacy often against the same people, so I decided I needed to cultivate a reputation for vengefulness. And by "decided to cultivate a reputation for vengefulness", I mean "Turkey betrayed me and I was filled with the burning rage of a thousand suns".

 

So my drive for revenge was mostly emotional instead of rational. But what I didn't do was suppress my anger, the way people are always telling you. Suppressing anger is a useful strategy for one-shot games, but in an iterated game, getting a reputation for anger is often more valuable than behaving in your immediate rational self-interest.

 

So I decided to throw the game to Germany, Turkey's biggest rival. I moved my forces away from the Italian-German border and invited Germany to take over my territory. At the same time, I used my remaining forces supporting German attacks against Turkey. The Austrians, who had been dealing with Turkey's betrayals even longer than I had, happily joined in. With our help, German forces scored several resounding victories against Turkey and pushed it back from near the top of the game down to a distant third.

 

Around the same time, Germany's other enemy France also betrayed me. So I told France I was throwing the game to Germany to punish him. No point in missing a perfectly good opportunity to cultivate a reputation for vengefulness.

 

If I had done the rational thing and excused Turkey's betrayal because it was in my self-interest to cut my losses, I could have had a mediocre end game, and Turkey's player would have happily betrayed me the next game as soon as he saw any advantage in doing so. Instead, I'm doing very poorly in the end game, but Turkey - and everyone else - will be very wary about betraying me next time around.

 

Study Seven: In-Group Bias as a Schelling Point


I made the mistake of moderating a game of Diplomacy at the SIAI House, which turned into one of the worst I've ever seen. The players were five SIAI Visiting Fellows and two of my non-SIAI friends who happened to be in the area.

 

Jasen came up with the idea of an alliance of the five SIAI players against my two friends. Although a few of the Fellows vacillated back and forth and defected a few times, he was generally able to keep the loyalty of the five Fellows until my two friends had been eliminated from the game relatively early on. Although normally the game would have continued until one of the Fellows managed to dominate the others, it was already very late and we called it a night at that point.

 

It's easy to explain what happened as an irrational in-group bias, or as "loyalty" or "patriotism" among the SIAI folk. Jasen himself explained it as a desire to prove that SIAI people were especially cooperative and especially good at game theory, which I suppose worked. But there's another, completely theoretical perspective from which to view the SIAI Alliance.

 

Imagine you are on a lifeboat with nine other people, and determine that one of the ten of you must be killed and eaten to provide sustenance to the others. You are all ready to draw lots to decide who is dinner when you shout out "Hey, instead of this whole drawing lots thing, let's kill and eat Bob!"

 

If your fellow castaways are rational agents, they might just agree. If they go with lots, each has a 10% chance of ending up dinner. If everyone just agrees on Bob, then everyone has a 0% chance of ending up dinner (except poor Bob). Nine out of ten people are better off, and nine out of ten of you vote to adopt the new plan. Whether your lifeboat decides things by majority vote or by physical violence, it doesn't look good for Bob.

 

But imagine a week later, you still haven't been rescued, and the whole situation repeats. If everyone lets you repeat your action of calling out a name, there's a 1/9 chance it'll be eir name - no better than drawing lots. In fact, since you're very unlikely to call out your own name, it's more of a 1/8 chance - worse than just drawing lots. So everyone would like to be the one who calls out the name, and as soon as the lots are taken out, everyone shouts "Hey, instead of the whole drawing lots thing, let's kill and eat X!" where X is a different person for each of the nine castaways. This is utterly useless, and you probably end up just drawing lots.

 

But suppose eight of the nine of you are blond, and one is a brunette. The brunette is now a Schelling point. If you choose to kill and eat the brunette, there's a pretty good chance all of your blond friends will do the same, even if none of you had a pre-existing prejudice against brunettes. Therefore, all eight of you shout out "Let's kill and eat the brunette!", since this is safer than drawing lots. Your lifeboat has invented in-group bias from rational principles.

 

Such alliances are equally attractive in Diplomacy. When the five SIAI Fellows allied against my two friends, they ensured there was a five-against-two alliance with themselves on the winning side, and successfully reduced the gameboard from six opponents to four. Although they could have done this with anyone (eg Jasen could have selected two other Fellows and my two friends, and forged an equivalent coalition of five), Jasen would have been at risk of five other people having the same idea and excluding him. By choosing a natural and obvious division in which he was on the majority, Jasen avoided this risk.

 

Rationalist Diplomacy


I'm interested in seeing what a Diplomacy game between Less Wrongers looks like. I'm willing to moderate. The first seven people to sign up get places (don't sign up if you don't expect to have enough time for about two or three turns/week), and the next few can be alternates. Doesn't matter if you've ever played before as long as you read the rules above and think you understand them. (We already have seven people. See the post in Discussion. If many more sign up, someone else may want to moderate a second game).

 

 

Footnotes


1: Source: "Nice Guys Finish First" in the Frameshift album Unweaving the Rainbow.

 

2. Alicorn wishes me to note that she considers anyone playing a Diplomacy game  without prior out-of-game-context agreements secured to have waived eir right to complete honesty from her, but the general principle still stands.

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Game Theory at Work was written by me, a devoted LessWronger.

2Scott Alexander10yWow. Didn't notice that. Thanks!

Diplomacy rant/warning!

Diplomacy culture is different in different cultures. The exchange between Eero Tuovinen and Valamir (Ralph) in this thread is particularly fascinating, and brings up a very good point: the game of Diplomacy is defined by the people agreeing to play it. If you do not agree beforehand what is within the game then you are playing different games, which is a very weird situation. "Let's play a game!" "Okay, e4." "Um, I rolled doubles so I go again. What's this about pawns?"

If you do agree beforehand, then you're all playing the same game. But two groups could easily choose different games and still call them both "Diplomacy"... here's Valamir's chosen game:

The entire design of the game of Diplomacy is to illustrate the trade off between short term gain and long term plans and the consequences for spending your political capital (aka trust and reputation) frivolously. Making a killer hose move to win a game today is SUPPOSED to have consequences on your ability to win in the future. That's the point...is winning this game really so important to you that you're willing to permanently decrease your odds of ever winning agai

... (read more)

I've noticed that even when people say "Let's play chess", they get confused when I reply "Okay, e4", like they were expecting to use a board.

4Ferd10yI'd be confused. d4 is better and everyone knows it.
5Carinthium10yJust checking, but which type are we signing up for?
4JRMayne10yI played Diplomacy a few dozen times in college, and the idea of side deals or even carry-over irritation at a prior stab is foreign to me. We would have viewed an enforceable side deal as cheating, and we tried to convince others to ally with us due to game considerations. Lying in-game simply isn't evil. Getting stabbed was part of the game. No one played meta-game vengeance tactics not because people didn't think of them, but because it seemed wrong to do so. Diplomacy's much more fun to play as a game, like any other, where you're trying to win the individual game. And if you're in a situation where a stab is likely to lead to a much better in-game situation, you should do it. The discussions in this post are about a game I do not think I would like. --JRM
3Zvi10yThis was exactly my reaction, and I'm preparing a potential top level post as a response - to me the game described in this article is not Diplomacy but rather one of the more common failure modes of those attempting to play Diplomacy. I've participated in both, and to me Eero's game both is Diplomacy and is in my opinion a vastly better game qua game. Incidentally, the other failure mode is not having enough time and ending the game after the opening or middle game, frequently in a four or five way draw.
1HughRistik10yI agree with Eero's perspective in general. But notice that he is an experienced player who plays with experienced players where everyone can "trust" each other to play to win. Another way that Diplomacy can lead to different games is disagreement over playing to win. What constitutes playing to win? Going for a solo win, obviously. But what if the game isn't going well and you have no chance of soloing, or your chances are low? Here are a couple examples. * You have a 40% chance of a solo with one strategy, and a 60% chance of a draw with a safer strategy. What should you do? * You are Turkey being invaded by Russia. Your elimination seems inevitable. You could do your best to slow the Russian invasion, but then Austria would take some of your territory. Except that even though Russian is your main invader, Austria stabbed you earlier and you are pissed at him. So is it justifiable to hand over your centers to Russia so he will expand more than Austria? If you've made a precommitment to Austria to give Russia your centers if he stabs you, does that make it OK? * You are Russia and you have nearly eliminated Turkey. But it's actually better to make Turkey your puppet regime, because you can use his fleets now rather than eliminating him and rebuilding those fleets under your own banner. Should he agree to be your puppet, or is that dishonorable by screwing over other people on the board? If you successfully expand, should you stab him later, or is that "dishonorable"? Different diplomacy groups may have different norms for these sorts of cases.
1PhilGoetz10yGood point. I'd consider it cheating someone made an enforceable out-of-game contract with another player. I wouldn't consider it cheating to throw the game to get a reputation for vengefulness. But if one player starts doing that, then everyone is forced to - and some people might not like that game.
0torekp10yThis point about Diplomacy culture illustrates one of the most important ways in which it's not particularly true that as stated in the OP (emphases added). The players aren't self-interested because, in the usual case, they're playing with friends and acquaintances. (Or even simply because they're typical human beings interacting with other human beings.) And the availability of external enforcement mechanisms has already been pointed out. Of course, game theory doesn't actually require self-interested actors either. At least not in any sense of "rational self-interest" which goes beyond "rational interest" or, for brevity, "rationality".

The game of Diplomacy I won, I won through an enforceable side contract (which lost me a friend and got me some accusations of cheating, but this is par for the course for a good Diplomacy game). I was Britain; my friend H was France... A lot of people made fun of me for this, including H, but in my defense I did end up winning the game.

I strongly agree with this Newbies' Guide:

You must always play each game fairly to give each player an equal opportunity to do well… don't sign up for a game with your best friend and have an unbreakable alliance from turn one... winning in these situations does not say anything about your skills as a Diplomacy player, only that you can win by cheating (well duh).

5groupuscule10yIf contracts using outside resources were legitimate it would also be okay for players to (consistently) offer cash rewards for cooperation. That would break the game pretty badly.
0thezeus1810yDoesn't iteration cause this strategy to be balanced out? After it becomes clear that two players have an unbreakable alliance, it's in the best interest of the rest of the players to destroy those two first in all future games. This passage from the TV Tropes page on the Scrub [http://tvtropes.org/pmwiki/pmwiki.php/Main/Scrub] is relevant:
5Kingreaper10yIn Risk, iteration will cause the player who always rolls 4-6 on all their dice to lose, because everyone will think they're an annoying cheater. Doesn't make it not cheating to use dice which only have 4-6 written twice. If you're playing a different game to the one people agreed to play, even if the game you're playing can be considered as metagame balanced, you're cheating.
1MichaelHoward10yThe games described in the post were online - they're normally played against different opponents each time. The game that's about to start is only planned to happen once. Only if iteration was a factor, and even then, that argument could be applied to most forms of cheating. Only if iteration was a factor, and even then, only in a sense that could be applied to most forms of cheating.
1thezeus1810yIt's really only applicable to forms of cheating which can be countered by non-cheaters ganging up on the cheaters. If the cheat causes an automatic win in every game, the scrub argument against its banning doesn't apply. But I agree, I was assuming iteration. Obviously, the scrubbiness of the rule against unbreakable alliances (and thus the cheatiness of the tactic), would depend on metagame circumstances.

I invited Clippy to play.

1PhilGoetz10yWhy would Clippy play Diplomacy? Did you offer him a paperclip for his alliance?
-1DSimon10yWhy would any human play Diplomacy? Did someone offer them a utilon (perhaps reproduction or food) for their alliance?
2TobyBartels10yFor humans, fun is a utilon. For Clippy? But there must be some reason that Clippy posts here at all, so this could just be part of it's plans to ingratiate itself with humans (particularly humans who might build AIs, I guess).
3DSimon10yWell, fun is a utilon at least partially because Inspector Darwin noticed that games are good training. Perhaps Clippy is motivated by a somewhat similar desire to use games as a means of understanding human behavior, or as a way of developing eir own understanding of game theory.

Jasen himself explained it as a desire to prove that SIAI people were especially cooperative and especially good at game theory, which I suppose worked.

Close, I was more trying to prove that I could get the Visiting Fellows to be especially cooperative than trying to prove that they were normally especially cooperative. I viewed it more as a personal challenge. I was also thinking about the long-term, real world consequences of the game's outcome. It was far more important to me that SIAI be capable of effective cooperation and coordinate than that I... (read more)

So my drive for revenge was mostly emotional instead of rational.

You mean the other way around, right?

my two friends had been eliminated from the game relatively early... it was already very late and we called it a night at that point.

This illustrates a basic design flaw shared by almost all board games involving war: one or more players are eliminated early and then have nothing to do until the next game starts. This flaw has been identified by the new wave of "German" game designers, whose games rarely involve war.

Another design flaw ma... (read more)

1PhilGoetz10yThat's usually a deliberate feature, not a bug. I call it "handicapping".
2JenniferRM10yRichard Garfield [http://en.wikipedia.org/wiki/Richard_Garfield] wrote an essay on the useful of game design terminology (can't find it via google for a link but I found a game review [http://www.gamecabinet.com/reviews/XPasch.html] where someone else apparently remembers the same article) where he borrowed the term " kingmaking [http://en.wikipedia.org/wiki/Kingmaker]" from politics. In Garfield's re-coining, the term describes situations where one or more players with no chance at winning are empowered by game mechanics to determine who wins in the end. When my family plays Settlers of Catan [http://en.wikipedia.org/wiki/The_Settlers_of_Catan], the winner is normally determined by kingmaking and a lot of the endgame fun comes from friendly metagame political wrangling (vengeful playacting, backrub offers, and such). If someone wins without any visible kingmaking on their behalf, we consider it a categorically superior sort of victory.
1Sniffnoy10yIs that usage really due to Garfield? I was under the impression it was much older than that.
1JenniferRM10yI remember reading an article by Garfield (this would have been in roughly 1998?) where he proposed the term as the kind of word that game designers need more of, and my memory of that reading (possibly simplified) was that he coined the term there. Now my guess is that he simply imported the term from political history to games, but I worked that out by tracking down references and discovering usage going back to literal king making in British history. Checking just now, google scholar contains essentially no references to game theoretic kingmaking during the 1990's. The terms "king" and "making" occur together, but it all appears to be political usage, a distinct re-use for websites whose links are especially critical in creating nearness relations, or accidental, as when talking about things made by Martin Luther King.

This leads me to wonder if any other Less Wrongers own a copy of Solium Infernum? I've had one game before which petered out near the end, but I suspect that playing with LWers could be a lot more rewarding.

For those who might be interested, Rock Paper Shotgun has a great AAR.

A quick summary of how it works: Satan has gone missing, and arch demons are vying to become the new ruler of hell. You have an unknown length of time to play, at the end of which you need to be the player with the highest prestige. There are a number of different tactics and strateg... (read more)

I would have made it with Eliezer, who has a consequentialist morality but, on account of the consequences, has said he would not break an oath even for the sake of saving the world.

Is there a link to an online explanation of this? When are the consequences of breaking an oath worse than a destroyed world? What did "world" mean when he said it? Humans? Earth? Humans on Earth? Energy in the Multiverse?

But I only trust Alicorn and Eliezer because I've discussed morality with both of them in a situation where they had no incentive to lie

... (read more)
0humpolec10yPrices or Bindings [http://lesswrong.com/lw/v2/prices_or_bindings/]
0PhilGoetz10yThanks! I had read that, but had forgotten about it. Perhaps EY's position makes more sense within timeless decision theory? Since it seems to be based on an absolute requirement for integrity of pre-commitment. On the other hand, he did not express disapproval of sinking the ship to stop the German nuclear bomb. What if Haukelid had had to promise not to harm the ship, in order to get access to it?

Religion is a special case of the enforceable side-contract in which God is doing the enforcing. God doesn't have to exist for this to work; as long as at least one party believes He does, the threat of punishment will be credible. The advantage of being able to easily make enforceable side contracts even in the absence of social authority may be one reason religion became so popular, and if humans do turn out to have a genetic tendency toward belief, the side contracts might have provided part of the survival advantage that spread the gene.

By the way, ... (read more)

I've seen it written that in Diplomacy, it's better to ally with countries that you don't share a border with, because it's harder to backstab someone you can't attack directly. ;)

Alicorn wishes me to note that she considers anyone playing a Diplomacy game without prior out-of-game-context agreements secured to have waived eir right to complete honesty from her, but the general principle still stands.

That she wishes you to note this is yet further evidence of her principled honesty!

0wedrifid10yShe appears to have also sacrificed her ability to communicate in game without costly signalling. Her word now conveys exactly zero information inside the game. That is a distinct disadvantage to her.
3Alicorn10yOne: I'm not playing. I could precommit to throw every game of Diplomacy without a "distinct" disadvantage because I'm not playing. Two: I don't lose the ability to communicate; everyone is assumed to be possibly lying in a game of Diplomacy, and I was just correcting the assumption that I would behave atypically. If I were playing, which I am not.
1wedrifid10yThe relevance of my statement is, of course, bounded by the relevance of yours. The counterfactual implications of a counterfactual as it were. You did not (counterfactually) lose any ability relative to a baseline. You lost ability relative to whatever benefits you would have gained via the principled honesty reputation which you have been trying to signal. I assume that you do, in fact, gain something in the way of trustworthiness by such signalling efforts outside of the game. Unless you are suggesting that any faith I have gained in your personal integrity is misguided? ;)
3JRMayne10yI must be misreading this. A principled, honest person would lie in a game of Diplomacy or Junta, or other similar games. Lying is part of the game. As I noted elsewhere in this thread, I strongly dislike the idea of playing these games within some real-world metagame framework. Further, I'd take a positive inference from someone who said, "I will lie for my own benefit in a Diplomacy game,' because it's clear to me that they are playing the same game I am. I have an awfully strong reputation for principled honesty (says me), but I'll tell you right now: When I promise you that Russia and I are sworn enemies and I desperately need you to move northward to fight the Red Menace, I may be moving in from the south to take some of your neglected property. For the good of the world, of course. And if you say afterward that I am a dishonest person, you need to play a different game. Or maybe I do. But you're just wrong in considering me dishonest. Or maybe I did misread this. Please correct my misinterpretation if I did.
0wedrifid10yYou are. This isn't about being a "principled, honest person". It's about winning. When I said "exactly zero" I was saying it with emphasis. You, given your stance, literally do not have the ability to communicate at all in a game theoretic sense without costly signalling. This doesn't mean you are a bad person and I definitely don't want to shame you into 'better' behavior. Because being unable to communicate effectively sometimes makes you lose, which makes me win. I'm considering now a situation in which 'Russia' (it was a game of risk, not Diplomacy per se) is a rival of mine and also an immediate potentially overwhelming threat to a neighbour of mine. I had power enough to defeat both of them, but it would be costly to me. I told the third party that I would not attack him on a different front without giving him a full turn warning. It didn't require a compact, any sort of agreement between us. It was just a fact. That player could believe me and move all his forces to fight Russia. Your word, however, would have been nothing. Russia would have weakened you sufficiently that another enemy would have overwhelmed you. I understand that you are playing a meta-game in which you shame people out of things like taking vengeance [http://lesswrong.com/lw/32u/diplomacy_as_a_game_theory_laboratory/2ya6?c=1] when it does not benefit them. That is your prerogative. I speak here not of what people should do, merely what works. Alicorn's declaration was regarding what her word meant in regard to whatever out of game arrangements she may make. I merely point out that sacrificing her ability to speak honestly and be believed in game is a strict disadvantage within said context. This is something that is counter-intuitive to many people - which is why I made a note.
0JRMayne10yThat doesn't seem quite right to me. First off, you've perhaps misread my vengeance comment. In-game vengeance may well be proper gaming; you're just not going to get a palpable carry-over for it into the next game. There's no shaming of the vengeful at all. Secondly, my commentary still has substantial value in a Diplomacy game. Trust, but verify and all. Diplomacy's about talking (usually; there are no-press games.) If you walked into one of my games, you'd have no advantage whatsoever for whatever trusty goodness you think you have. Thirdly, I still view the intrusion of real-world considerations onto game ethics as undesirable. If it's Survivor and you don't eat if someone doesn't kill the rabbit, then it's a different situation. But each game has it's own rules; if you communicate your bridge hand through hand signals, you're a scummy cheat - even if it helps you win. I don't do that, because it's wrong. Certainly, making private real-world side deals strikes me as cheating, and would be in my circle. Trying to cash in on a rep for real-world honesty strikes me as misguided. I hope this helps clarify my position. --JRM
2shokwave10yBridge specifies that communicating information about your hand is against the rules; Diplomacy says that making deals is specifically part of the rules. Diplomacy doesn't provide an enforceable contract, sure, but that just means that finding a method of creating enforceable contracts gives you an advantage.
0[anonymous]10yWe do not agree.
2Alicorn10yI would consider it unethical to lie to someone who I have some reason to believe wouldn't have waived their right to honesty. Someone who believes that I won't lie to them might not be disposed to waive that right. So I couldn't ethically take advantage of the sort of misunderstanding Yvain had about the scope of my ethics.
0wedrifid10yDon't misunderstand me. I don't suggest that you were making a mistake and I respect and acknowledge proactive honesty of the type you mention. I just note that in itself it is disadvantageous within said context. It had incidentally occurred to me that so sabotaging yourself, conditionally on out of game arrangements could be used to benefit yourself (in game) by providing more incentive for others to make such arrangements. It struck me as somewhat ironic that granting oneself the ability to betray actually could amount to a self destructive signal used for the purpose of influence. (Again, just what could be done, not what you are doing.)

There are now seven people who want to play but didn't make it into the original game: Kevin, Randaly, AlexMennen, tenshiko, purpleposeidon, MisterInteger, and Thausler. That's enough for another full game. If anyone else wants to organize/moderate a game, I can hook them up with the appropriate software to make it (relatively) painless, or they can go to www.playdiplomacy.com once it's organized and do it semi-automatically.

2Randaly10yI'll organize it.
0tenshiko10yWhat's the planned turnaround on contacts for players in this secondary game (assuming it's established that the seven mentioned in the parent of your comment is the intended group)?
1Randaly10y2 days for orders, and 18 hours for retreats and building.
0Elizabeth10yI would also quite like to play.
0HughRistik10yHugh Ristik would also be interested in a second game. I am also experienced with Diplomacy.
0[anonymous]10yAs would wedrifid. I have no experience with Diplomacy. I do have some experience with 'diplomacy'. I hope we get to kill stuff too. That kind of diplomacy is all kinds of fun!

I find it amazing that examples like the religious person swearing by god and his/her eternal soul counts for anything. Surely god knows that it was your in-game character that said it, and won't hold it against you.

Similar argument only more so for the Eliezer & Alicorn situations -- your second footnote confirms that it would be a mistake to trust what people have said on LW as applying in-game.

Small typo:

Not only does it prevent your opponent doesn't defect out of sheer greed

5PhilGoetz10yGod has the advantage of being somewhat inconsistent, having unclear rules, and setting examples (eg the book of Job) where he breaks his own rules, so no one can confidently rules-lawyer God.
3Alicorn10yIn my case, I could be trusted in-game if, before the game began, I promised to be trustworthy, or if some of the people I was playing with expressly did not waive their rights to honesty. In-game, if someone suddenly announced that they wanted to maintain that right for themselves, I would respect it, but I might do so by leaving the game entirely. Since I expect I would detest the game, though, I have no intention of playing it (which means I have no reason to lie here).

Diplomacy is an amazing rationalist game. I've played it a bunch of times.

One of the other psychological aspects is avoiding committing the Typical Mind Fallacy. Don't assume that just because you think a certain plan is in the interest of someone else, that they will see it the same way. This sounds simple, but it's not.

If you try to set up an alliance with someone, both people will tell the other that they feel the alliance is mutually beneficial. But secretly, your partner has doubts about the benefits of the alliance. You believe that the alliance is o... (read more)

OK, I've put the second game up in the Discussion Section for everybody who's already expressed an interest in playing.

I'd suggest to take a look at the 1900 variant, it's quite close to the original but provides much more interaction between the distant powers, giving strong reasons for Britain to talk to Turkey since the early game.

"Austria knows that ey would have no incentive not to break his promise once Austria's given him the help he needs"

HIS promise once Austria's given HIM the help HE needs?

You are sexist, sir.

I love Diplomacy. Unfortunately, I tend to find playing games very intense and can't spare the energy for that right now.

Among the seven studies, the third one is denoted as "scenario". I suspect it is by mistake.

Besides that, I would be interested to play. Do you plan to do it by e-mail? Using a game server like webdiplomacy.net one can play without a moderator.

0TobyBartels10yI've played here before; I quit because it took too much time, but that's the nature of the game, not the website. Games between strangers (or between people who've met on the site) are the norm there, but games between new members who come just to play with each other are also welcome.

I'd also like to play, although I haven't been on LW long enough to be considered highly rational. Is it best I'm in or not?

But I only trust Alicorn and Eliezer because I've discussed morality with both of them in a situation where they had no incentive to lie; it was only in the very unusual conditions of Less Wrong that they could send such a signal believably. Religion is a much easier signal to send and receive without being a moral philosopher.

In games like this, my strategy (or at least my ideal strategy - I haven't actually played enough games like this to do it) is to declare that I will keep my agreements in about 70% of the games I play, a statement I try to adhere... (read more)

3JGWeissman10yIf I have a choice of cooperating with you, or another player that keeps eir agreements 80% of the time, guess who I am going to cooperate with.
2RolfAndreassen10yThat creates a bidding war with a hard limit at 100%, and personally I would not find a claim of 100% honesty in Diplomacy games credible. 70% seems doable; the closer the claimed honesty ratio is to 100% the less credible it is.
2JGWeissman10yLet credibility be established by track records.
4RolfAndreassen10yOf course, but then they are not credible in advance. Also, it would take many agreements to reliably tell the difference between 70% and 50%; even between 70% and 30%. If you play 50 games of Diplomacy - and by the luck of the draw, you might not be in a position to make agreements with someone every time; Turkey and England presumably don't have a lot of contact - then 70% is 35 games in which no agreement is broken. 25, which is 50 percent, is less than two sigma away. And fifty games is a lot of Diplomacy.
-1Aurini10yYou could pre-commit to rolling percentil dice.
0RolfAndreassen10yYes, but could you credibly do so? You can commit to anything you like; it's the credibility, not the commitment, that is the problem. Credibility can only be established by long-run tests, and then you run into the problem of distinguishing 70% from 50%.
1JenniferRM10yIf someone just blindly asserted that they'd "try in general" to achieve some honesty percentage and didn't have logs of past games and similar paraphernalia as evidence of honest calculation I would tend to dismiss it as "verbal rationality signaling" that wasn't likely to be calibrated enough to matter. Real calibration takes paper and pencil. However, something even more rigorous seems feasible using bit commitment and coin flipping [http://en.wikipedia.org/wiki/Commitment_scheme] protocols from cryptography. You could do the cryptographic protocol at the beginning of the game with the desired probability of being required to lie and then reveal your "lying commitment status" at the end of the game to demonstrate your meta-trustworthiness. The meta-trustworthiness parameter seems like the thing that Yvain was getting at with philosophically minded ethicists, because such people have demonstrably committed to meta-trustworthiness as a part of their real world identity -- as a part of their character [http://www.newadvent.org/cathen/03584b.htm]. Assuming you have good character, the trick would be that at the beginning of the game you'd really have pre-committed to either lying or truth-telling and your commitment status becomes a hidden variable whose value people might reasonably guess from your behavior in the game, so there would be another layer to the gameplay where you try to avoid doing anything that would reveal your commitment status one way or another because the ambiguity is finite and potentially valuable. You could imagine a game where everyone at the beginning commits "pairwise privately" to varying levels of trustworthiness with everyone else and then estimating the full trust network of probabilities and commitment states (and other player's estimates knowledge about the state of the network) becomes part of the task over the course of the game. Actually, this version of the game sounds fun. If I had more free time I'd be tempted to get into an
0DanielLC10yYou could roll the die so everyone else can't see them, then take a picture with your cell-phone. At the end, you can prove that you were doing what the die said.
1NihilCredo10yNothing could stop you from rolling the die until you get the wanted number, and then only publishing one result. To be credible, you'd need a RNG that you can't use without everyone else knowing that you did (if not the specific result), which usually means a third party. Online D&D uses trusted die-roller websites that keep logs of all the rolls made under one's name; you could have a variant where they just publish a hash of the results, rather than the results themselves.
1Bongo10yOne thing about the 70% strategy is that you will be expected to defect in the top 30% of situations where you would gain the most from it, and to cooperate in the bottom 70% of situations in which you're not passing on such a juicy defection opportunity anyway.
4Kaj_Sotala10yNot if I determine my loyalty by a secret die roll before the game.
0[anonymous]10yI was going to determine all of my moves using I Ching.
0PhilGoetz10yYou could probably write out an equation that would take the distribution of decisions (expressed in payoff for defection vs. cooperation), and compute the optimal probability distribution (as a function of expected value for defection, or ratio of cooperation/defection payoff, perhaps) to use for this strategy. Bongo's comment rightly implies that the result will depend on whether other players observe the probability you will betray them as a function of payoff, or just the probability overall.

But suppose eight of the nine of you are blond, and one is a brunette. The brunette is now a Schelling point. If you choose to kill and eat the brunette, there's a pretty good chance all of your blond friends will do the same, even if none of you had a pre-existing prejudice against brunettes. Therefore, all eight of you shout out "Let's kill and eat the brunette!", since this is safer than drawing lots. Your lifeboat has invented in-group bias from rational principles.

Suppose further that you have green eyes while everyone else on the boat has gray eyes.

Maybe you don't want to go down this road after all.

I would have made it with Eliezer, who has a consequentialist morality but, on account of the consequences, has said he would not break an oath even for the sake of saving the world.

Of course, he has good reason to lie about that*. But having told that lie, he can't break an oath for soemthing that is less valuable than maintaining the lie; so you're safe believing him in Diplomacy. But if you were a Paperclipper, you'd be an idiot to believe him if he vowed to help you achieve your goals.

If rational, he will only be telling the truth if he believes tha... (read more)

I'd like to play, either as an alternate or in a second game.

I have played Diplomacy in a very close-knit community, playing three turns a week. It's really pretty marvelous, especially when there is the possibility of face-to-face, long term alliance-building.

I've been a lurker here for a good six months. I feel like a game of Diplomacy would be a fabulous way to "join" Less Wrong more completely. How do I sign up?

This sounds fun! Where do I sign up? Here?

Hiding the names of the players, that is, knowing only the country, would likely make pre-game contracts impossible

1TobyBartels10yNot necessarily; you can prove your identity by making out-of-game predictions of your own in-game behaviour.

I'd love to be in, if my spot hasn't already been taken by more interesting people.

I'll sign up as an alternate, or I'll play if we get another game going. By the way, this program is great for online diplomacy games: http://realpolitik.sourceforge.net/

Jack, Rolf, Kaj, Carinthium, Prase, Perplexed, and Vaniver have spots in the game and should check the Discussion section ASAP. Kevin and Randaly are alternates and may also want to check the Discussion section .

I once made this comment at Overcoming Bias, note Brian Moore's reply.

I'm in- will this be by email?

I'll play... I played a bunch in high school and more recently played about 1.5 games at Benton. Also I likely have more free time than anyone else posting here.

I'm interested in playing! (Used to play once a week for a year or so, but that was a few years ago now.)

If there is still an opening, sign me up. I assume there are maps available online.

[-][anonymous]10y 0

Diplomacy rant/warning!

Diplomacy culture is different in different cultures. The exchange between Eero Tuovinen and Valamir in this thread is particularly fascinating, and brings up a very good point: the game of Diplomacy is defined by the people agreeing to play it. If you do not agree beforehand what is within the game then you are playing different games, which is a very weird situation. "Let's play a game!" "Okay, e4." "Um, I rolled doubles so I go again. What's this about pawns?"

If you do agree beforehand, then you're al... (read more)

EDITED: On second thought, I can't pledge to set aside the time it would take, indefinitely.

[-][anonymous]10y 0

Please don't give people excuses to spend time playing games.

India was played by my friend A, who I sometimes have philosophical discussions with and who I knew to be an arch-conservative religion-and-family-values type. I decided to try something which, as far as I know, no one's ever tried in a Diplomacy game before. "Do you swear in the name of God and your sacred honor that you won't attack me?" I asked ... In the future, I will seek out A for alliances more often, since I have extra reason to believe he won't betray me; this will put A in

... (read more)

I'd like to play.

I'm in. Haven't played in forever.

0marchdown10yI've never played Diplomacy, but if there is a network game brewing, count me in.

Sounds like SIAI needs more people who enjoy playing devil's advocate.

Hmm, or maybe the way that the group was selected provided some sort of selection bias against those sorts of people...

P.S. On the topic of "they," I feel more comfortable with something else.

EDIT: Like me, apparently, who just can't resist clasting that icono.