I play a lot of video games. Enough to occasionally find a rare gem like the puzzle game Understand. Its inspirations include the games The Witness, Baba is You, and Zendo, as well as the 2-4-6 task in psychology. Understand costs 4$ (3.3€) and is available for Windows and macOS on the Steam game client. (EDIT: For Linux compatibility, see this discussion.)
But before I get to the game itself and why I recommend it on Less Wrong, a brief aside:
Why Recommend a Game on LW?
I've easily played >1000 video games, including most critically acclaimed puzzle games irrespective of popularity. That's a lot of time spent on leisure. When gamers compliment a game, they call it "addicting", which is a pretty insane state of affairs. In any case, I would not recommend most puzzle games or even programming-style optimization games to a community interested in understanding and improving the world. Skills learned in any particular game rarely generalize, and the opportunity cost of spending time on potentially addicting games is high.
With that said, this is the one game I recommend here. I think it does something genuinely unique which could be used to practice a few core rationalist techniques, and I consider its design and presentation far from addicting.
Anyway, with that out of the way, let's get to the game.
What is Understand?
The premise in Understand is delightfully simple: each level consists of a couple of screens with a common but hidden ruleset. Your task is to draw a path on each screen (controlled with the mouse) which satisfies these rules (represented by one or more dots below the screen). So early on the challenge is almost entirely in discerning the hidden rules.
For this you get various bits of feedback. The game tells you how many rules there are, and when you draw a path it tells you which specific rules it fulfills. The first screen in each level shows you a valid path which fulfills all rules, and the next few screens are cleverly designed to teach by example. So you'll use deduction and trial & error to draw paths and uncover the rules.
The game consists of ~130 levels à 5-10 screens, which makes for a lot of game, but you can already get something out of it within the first hour of play, and there's no need to play through it in its entirety.
(My more in-depth review of the game, which may be mostly of interest for gamers and completionists, can be found here.)
If you'd like to see how that plays out in practice, I've recorded a 1-minute playthrough of an introductory level. (Otherwise feel free to skip this section.) Shortcomings: This example is necessarily a bit fake since I already knew the rules of the level; introductory levels in puzzle games are rarely particularly challenging or innovative; and the sound got a bit clipped due to the recording software.
On the first screen, I copy the suggested path. Then I try an arbitrary simple path which is accepted. On 1-7-3, the third screen, I try circle-square paths which don't work, then a circle-circle path which does. On 1-7-4, a path through all circles and some squares (or vice versa) fulfills the first rule but not the second, while a path through all circles or all squares (but not both) fulfills both rules. By this point I figure I've understood the rules (something like Rule 1: The path must go through all symbols of one type. Rule 2: The path must not go through any other symbols, or equivalently, all symbols on the path must be the same.) and solve the rest of the screens.
Understand for Rationalists
Understand is a rarity in that it relentlessly asks the player to form and test hypotheses while only providing very limited feedback; it's a pretty cerebral experience. For me playing it feels like doing experiments (drawing paths) in a very simple 2D world, and so to succeed at it requires practicing some of the same skills required in experimentation and truth-seeking. Those include:
- Avoiding positive bias: Like in the 2-4-6 task, it's often trivially easy to find a valid path on the first few screens, at which point one might be convinced one knows the rules, even if they're actually something else entirely.
- The scientific method, including forming hypotheses ("I wonder if rule 1 is that the path must begin on a star shape."), making predictions ("So if I begin the path on the star shape, rule 1 should be marked as fulfilled."), and falsifying them ("So let me start the path on another tile and see what happens.").
- Noticing confusion or surprise: "I've solved all screens so far based on <complicated hypothesis for rule 1>, but now on this screen I can't find a valid path. Is that because this screen is difficult, or because my interpretation of the rule is wrong?"
- Doing efficient experiments: In principle all screens could be solved by trial and error and without understanding the rules, but in practice the search space quickly becomes prohibitively big. So instead you have to discern the rules, but the space of conceivable rules is also too big... so you have to make hypotheses and run experiments in a way that maximizes the information you gain.
- Extracting as much information as possible from limited and possibly adversarially filtered evidence: "Why do the first few screens look like this? Is the developer trying to hint at something? Or is he maybe trying to trick me into pursuing a wrong direction?"
Ultimately, I'm recommending Understand here as potentially a decent tool to practice some of those core skills of rationality in a low-stakes environment. For instance, I picked up the skill of Noticing Confusion via the Sequences and HPMoR, and nowadays I constantly get good use out of it; but I never got started on many other techniques suggested on the site due to lack of training opportunities to turn them into habits. So I'm hopeful Understand could be one such training opportunity for skills like the above, especially for those of us who aren't able to interact with other rationalists in person.
That said, while most people play video games by themselves, I can even imagine Understand as a decent cooperative experience (with multiple people sharing hypotheses and one person controlling the mouse), e.g. for couples or group houses. Unfortunately the game is not available on smartphones, which makes this more cumbersome.
Suppose, I'm interested. Now what?
Finally, if this post prompts you to try this game, I would love to hear your experiences.
Thanks to Duncan Sabien and the LW feedback service for feedback on an earlier draft.
PS: As I wrote in my full review, the game is long and occasionally gets difficult, in that some screens are hard to solve even if you've discovered the rules. But I'm happy to provide hints and solutions upon request.
PPS: If you're intrigued by the game and have a Steam account, but you balk at the price or you didn't find my writeup convincing enough to spend your own money, I'll sponsor some copies (as Steam gifts) to people with 100+ karma on the site. Just ask in a comment or private message, and include a link to your Steam profile. In exchange I'd appreciate a comment with your experience of the game.