from Hacker News

Game theory illustrated by an animated cartoon game

by felineflock on 5/19/25, 4:28 PM with 74 comments

  • by hayst4ck on 5/19/25, 11:37 PM

    This is one of my favorite things on the internet, but it focuses on the positive side of the story which is that groups of people cooperating can defeat a bunch of people who cheat each other. That's a pleasant message.

    Unfortunately, I think the corollary is much more important. What this clearly shows is that on an extremely fundamental level, getting cheated or cooperating with people who act in bad faith is what creates the cheating. If you tolerate bad faith, you ask for more bad faith behavior.

    If you believe in personal agency and personal responsibility and don't believe in magical thinking, then it shows on a very mathematical level that your own weakness, the ability for someone to take advantage of you without consequences, is what creates defection rather than cooperation.

    The lesson is clear, that if you want a world you want to be a part of, then you must become powerful and choose to use that power for good.

  • by tiffanyh on 5/19/25, 7:27 PM

    Vertasium has a great video talking how Tit-for-Tat (Copycat) wins as a strategy (and how there was a math competition that proved it as well)

    https://www.youtube.com/watch?v=mScpHTIi-kM

    ---

    This seems like a nice rebuild of the math competition performed years ago (as talked about in the video link above).

    Direct link to that part of the video: https://youtu.be/mScpHTIi-kM?si=yzZxyeYw4cJA-i37&t=583

  • by gcanyon on 5/20/25, 12:13 AM

    No conversation on game theory is complete until someone brings up Golden Balls, and in particular this amazing moment (warning: terrible audio quality). https://www.youtube.com/watch?v=S0qjK3TWZE8

  • by ChicagoBoy11 on 5/19/25, 7:46 PM

    The Evolution of Cooperation is one of the best non-fiction book I've ever read. Through basic algebra it lets you in on appreciating such a deep and profound idea.

  • by netbioserror on 5/19/25, 6:33 PM

    I remember that in older formal game theory tournaments, a punish-once single-retaliation strategy won out. It was unconditional on copying, simply that if the opponent cheated, you cheat back once and then forgive until another cheat. Another form of Golden Rule approach. But I think those tournaments were under simpler conditions than the one here.

    I like the incorporation of miscommunication, and being able to change the parameters.

  • by NullHypothesist on 5/19/25, 5:53 PM

    Found this ~10 years ago. Still one of the best things i've ever come across on the internet.

  • by yubblegum on 5/19/25, 8:10 PM

    So this little game actually amplifies the distinction between "game theory" and (let's call it) 'relationship theory'. In the former you rely on strategy. In the latter, you rely on established trust.

    You run the game once and at the end you are given 'character' headsup on the participants. Next time around playing the same game, you know who is who.

    p.s. In effect the distinction can be generalized as 'depth of priors' for the 'bayesian game'.

  • by itsthecourier on 5/19/25, 6:36 PM

  • by krisoft on 5/20/25, 11:08 AM

    I disagree with the phrasing right the first question it asks.

    It says "Let's say the other player cheats, and doesn't put in a coin. What should you do?" and the two buttons are "cheat" and "cooperate". But if the other player doesn't put a coin in then not putting in a coin is not "cheating". It is simply not playing the game with that person.

    Cheating would be where you say you will put in the coin (or have already put the coin in) but not doing so.

  • by Tsarp on 5/20/25, 11:49 AM

    This is really the best ways to explain basic game theory to anyone. It wasn't until some excellent Profs in Grad school that I finally understand some of the most basic concepts, but would always find it hard to explain to friends and family.

    I also think game theory is one of the most important philosophies/life-lessons to understand as you go through life and this is an excellent resource to get people started on the basics.

  • by 0cf8612b2e1e on 5/19/25, 10:32 PM

    Radiolab had a story about this idea that I enjoyed.

    https://radiolab.org/podcast/104010-one-good-deed-deserves-a...

  • by fracus on 5/20/25, 1:40 AM

    This web site was so enlightening. I imagine it could often be difficult to put theory to practice as in real life there are so many variables to consider and many of them we can't quantify. Some of the demos illustrated complete opposite results due to a 1% change in the miscommunication variable. But I will say the 3 main takeaways they give you were more general and certainly applicable to real life.

  • by drdrek on 5/20/25, 2:05 PM

    One of the things I take is that if you keep the game the same but turn the punishment for both cheating really high cooperation blossoms even with high degree of miscommunication. Bring back hanging and quartering for petty crimes!

    In all seriousness Game Theory fails in reality because it cannot account for the players changing the game.

  • by Nopoint2 on 5/20/25, 7:28 AM

    I think that detective isn't the correct way to exploit copycat. A character which cooperates, but cheats at random, and keeps defecting if you retaliate, could push the balance towards cooperators. Grudgers, not forgivers, also win in high error scenarios for some reason, as long as enough rounds are played.

  • by Digit-Al on 5/20/25, 9:31 AM

    If the creator is reading this, I was having problems with the viewport on my tablet. I can't scroll around the page and in portrait mode, stuff disappears off the side of the page, and in landscape mode stuff disappears off the top and bottom of the page.

  • by pella on 5/20/25, 3:41 AM

    https://ncase.me/trust/notes/ ( NOTES: "The Evolution of Trust" )

  • by xpe on 5/19/25, 7:42 PM

    If you want the take-aways, click the next-to-last navigation circle on the bottom of the screen. I won't paste the spoilers here, because I think it would detract the experience.

  • by zharknado on 5/20/25, 1:22 AM

    Fantastic! Top notch explainer and engaging game.

    To me it’s important to say that tit-for-tat and the Golden Rule are not the same. My understanding of the two are very different.

  • by searine on 5/19/25, 9:26 PM

    This makes me think about The Dark Forest and the chain of distrust that results from lightspeed communications at stellar scale. The universe is harsh...

  • by pmkary on 5/20/25, 11:55 AM

    One of the most "old but golds". I smile every time this makes it into the top here.

  • by adi_lancey on 5/19/25, 5:53 PM

    this is pretty cool, very nice explanation of concepts I hadn't touched since undergrad econ

  • by redbell on 5/20/25, 1:43 PM

    Game Theory is a vast concept and I believe this work would be better classified under Prisoner's Dilemma (https://en.wikipedia.org/wiki/Prisoner%27s_dilemma), which is by definition:

      The prisoner's dilemma is a game theory thought experiment involving two rational agents, each of whom can either cooperate for mutual benefit or betray their partner ("defect") for individual gain. The dilemma arises from the fact that while defecting is rational for each agent, cooperation yields a higher payoff for each.
    Also, in the second game, it says:

    ..but if you cheat & they cooperate, you gain three coins at their cost of one. (score: +3 vs -1) Therefore: you "should" still CHEAT.

    Yes, technically and mathematically, it's 100% correct but morally, ethically and/or emotionally, it hurts.. a lot. Personally, I would never, ever do that!

  • by gowld on 5/19/25, 6:28 PM

    playing time: 30 min • by nicky case, july 2017

  • by badmonster on 5/19/25, 9:41 PM

    very cute!

  • by derbOac on 5/19/25, 11:50 PM

    Now add communication between players to repeated trials.

  • by clueless on 5/19/25, 6:25 PM

    spoiler alert: is copycat strategy the reason united states feels like it's becoming more like the rest of the world, more authoritarian?