alt.hn

5/19/2025 at 4:28:18 PM

Game theory illustrated by an animated cartoon game

https://ncase.me/trust/

by felineflock

5/19/2025 at 11:37:59 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 hayst4ck

5/20/2025 at 1:02:41 PM

>If you tolerate bad faith, you ask for more bad faith behavior.

Yet some bad faith behavior comes from misunderstanding, so to be completely intolerant of perceived bad faith behavior would be the same as entering into the endless "tit-for-tat" cheating loop mentioned on the site

"I'm intolerant of your (perceived) bad faith (because you're intolerant of my (perceived) bad faith)"

Works when perceptions aren't muddied, but that is rarely the case

>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.

I agree broadly, but that logic is also the cause of a lot of cheating

"I cheat because they cheat"

"I need nuclear weapons because they have nuclear weapons"

Tit-for-tat is a great strategy, but it's not a _dominant_ strategy

I think that's the most important point the website makes

by alickz

5/20/2025 at 2:52:14 PM

In sports it doesn't work with the individual, either tit-for-tat or just succumbing to bad behavior.

Instead there are central organizations created by the players and teams together, and they agree on rules and establish referees and processes so on.

by Gravityloss

5/20/2025 at 12:19:04 AM

I feel like your comment sums up many life lessons. It's also the reason I stopped believing in extreme leftism as I matured. I think as young idealists we think "Surely if we just gave the government a lot more tax money, they'd solve the problems we all say we care about" and "Surely if you just give freely to whomever says they're in need, they won't cheat the system!"

Later I started to see the patterns where government spends most of the money lining the pockets of the well-connected, and then on the micro level how many people take advantage of any method of unjust enrichment, given the chance, and you start to desire much more accountability from all parties. And yes, things like, say, exhaustive income verification to qualify for benefits definitely hurts those who are playing by the rules the whole time. It's the cost of having trashy individuals in society who exploit everyone relentlessly.

by xp84

5/20/2025 at 3:31:34 PM

> I feel like your comment sums up many life lessons. It's also the reason I stopped believing in extreme leftism as I matured. I think as young idealists we think "Surely if we just gave the government a lot more tax money, they'd solve the problems we all say we care about" and "Surely if you just give freely to whomever says they're in need, they won't cheat the system!"

As an older leftist, what you describe looks more like the liberal (centrist) view. Actual leftists think the current system is broken. Cops are not acting in good faith using tax payer money, so we should defund the police departments to some degree and divert those funds to social programs to help the vulnerable. Politicians and Congress people (including Democrats) in office are not acting in good faith and should be barred from trading individual stocks to prevent insider trading.

by gitremote

5/20/2025 at 6:19:21 PM

> Politicians and Congress people (including Democrats) in office are not acting in good faith and should be barred from trading individual stocks to prevent insider trading.

No objection from me there.

> defund the police departments to some degree and divert those funds to social programs

I will just say that I have zero faith that the "social programs" will do much besides serving as jobs programs for people with degrees that would otherwise not be useful to society. Meanwhile, less cops and less support for the idea of policing leads to more of the exact same opportunistic bad behavior that I was talking about. There's a statewide experiment on this topic that's been going on for years, called California.

by xp84

5/20/2025 at 10:35:05 PM

> I will just say that I have zero faith that the "social programs" will do much besides serving as jobs programs for people with degrees that would otherwise not be useful to society.

You're imagining it wrong.

Critics argue that police officers and departments are tasked with an overly broad range of responsibilities, leading to an over-reliance on law enforcement to address complex social issues such as homelessness, mental health crises, and substance abuse. To address this, some activists advocate for the "unbundling" of services, a model in which specialized response teams take over many responsibilities traditionally assigned to police. These teams could include social workers, emergency medical technicians, conflict resolution specialists, restorative justice teams, and other community-based professionals.

Police officers may be particularly badly suited for some community issues, such as mental health crises. One in four people who are killed by the police have severe mental illness. Some activists argue that mental health professionals may be more appropriate responders in non-emergency situations involving mental health crises. They also suggest that diverting funds to mental health treatment and support could lead to improved outcomes.

A 2020 paper by researchers at the RAND Corporation argues that the police are often given too many roles in society and asked to solve issues that they are not properly trained for and that would be better suited for professionals such as mental health, homelessness, drug abuse, and school related violence.

https://en.m.wikipedia.org/wiki/Defund_the_police

by gitremote

5/21/2025 at 10:37:04 PM

Seeing the meth addicts and schizophrenics (and probably some who are both) who get so out of hand that police get called, dealing with them is a dangerous job. I'd rather train police better, than get body armor for a psychiatrist so they don't get bitten by someone having a "mental health crisis." Also highly trained mental health professionals are going to cost a lot more than police, and they probably won't want to work nights and weekends.

Also, when cops are called due to a "mental health crisis" that is sometimes because that person has caused enough alarm that the people around them are in legitimate fear for their safety. Unless the "mental health crisis squad" has lights and sirens and 911 can dispatch them quickly at all times, they won't be sufficient to deal with the problems. When they can't talk them out of their delusions and get physically threatened as well, they'll probably just call the police.

DTP is operating from an attitude which assumes that police can't be better trained and that this other group of highly educated professionals should be turned to instead -- explicitly to replace police jobs, which is to be expected since it's a philosophy primarily promoted by the elites (college educated). Al lot of law-abiding regular people of many races and backgrounds, actually don't have toxic relationships with the police and don't want less policing.

by xp84

5/21/2025 at 6:41:32 PM

> Later I started to see the patterns where government spends most of the money lining the pockets of the well-connected

It is definitely not most of the money in developed countries. Being cynical is fine, but don't throw the baby out with the bathwater. Governments do enormously important and valuable things with most of the money. Just take a look at where money is spent in the budgets of developed countries.

by dinfinity

5/20/2025 at 12:36:02 AM

It looks like Copykitten is the sweet spot to me, with a focus on keeping miscommunication to a minimum. I wonder where, between 0% and 1%, there is a noticeable deviation, because I find the idea of the Copykitten more nuanced than the copycat, but the copycat always wins somewhere between 0 and 1.

by ericrosedev

5/20/2025 at 3:16:46 AM

> 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.

This particular lesson we've seen play out time and time again at a state level. Europe, USA, Singapore and even China.

The best thing that happened was corruption was either kept out or effectively eliminated.

When leaders are bad actors, it's pretty obvious, but an explicit example is the Philippines in the 50's-60's and how its economic powerhouse was squandered away.

Today, Vietnam is in the process of cleaning house and showing dividends while Indonesia really could really do amazing stuff if it go its act together.

by irjustin

5/20/2025 at 2:52:42 AM

> 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.

This is also a reasonable definition of a functional democratic society.

> If you believe in personal agency and personal responsibility and don't believe in magical thinking ...

  No man is an island, entire of itself; every man is a piece 
  of the continent.[0]
> 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.

Or perhaps a different lesson is that if you want a better world to exist, choose to live it. Sometimes there will be those which do not share this vision and actively work against your choice.

The question then becomes:

  Do you allow bad actors to determine who you are
  or is who you are orthogonal to what bad actors do?
Note that "power" has no relevance to the answer of this question.

0 - https://www.brainyquote.com/quotes/john_donne_101197

by AdieuToLogic

5/20/2025 at 1:54:58 PM

> Or perhaps a different lesson is that if you want a better world to exist, choose to live it. Sometimes there will be those which do not share this vision and actively work against your choice.

So you need the power to abide by your choices and not others'. I think the colloquial understanding of "power" is somewhat different than I want to convey. Power is potential, the ability to affect or effect, control[0]. Violence can be powerful, because a dead foe can't hurt you. Nonviolence can be powerful, because a dissuaded foe can't hurt you. Who you are determines what you do. What you do reflects who you are. The path you are walking on, whether to your design or not, requires power to prevent straying.

[0] https://en.wiktionary.org/wiki/power

by vacuity

5/21/2025 at 4:02:16 AM

> Power is potential, the ability to affect or effect, control[0]. Violence can be powerful, because a dead foe can't hurt you. Nonviolence can be powerful, because a dissuaded foe can't hurt you.

I was going more for the "be the change you want" perspective than what perceived power can accomplish. Ultimately, power is an illusion and consumes rather than enables.

> Who you are determines what you do.

Technically this is correct. However, it ignores choice and the value of personal growth found in honest introspection.

> What you do reflects who you are.

Very true. And if one chooses to do something different than what would have been done as an earlier version of oneself, does that not reflect growth?

> The path you are walking on, whether to your design or not, requires power to prevent straying.

Choice is not power, even though it is powerful, unless the assumed one of the multitude of definitions cited is the first:

  The ability to do or undergo something.
Which is incongruent with the implication of what I originally quoted:

  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.
  
So which is it?

by AdieuToLogic

5/21/2025 at 9:08:24 PM

You're going from a conventional understanding of "power", along the lines of how it is discussed in politics. I'm suggesting an alternative understanding. Power can mean the enabler of an action. Power can mean the quality of being able. Power is neither good nor bad; but power can stand in relation to a context that is good or bad. Power is associated with mostly anything that has meaning: a weapon, a sentence, a conviction, an innate ability, a fortune, a name. Why can police beat down nonviolent protestors? Because the police are powerful. Why can an idea become a movement? Because the idea, and the people who participate, are powerful. Choice is powerful; to have choices and to make choices involves power. A drop of water has the power to fall, gravity has the power to make it fall, and I have the power to reach out and catch the drop. There's power in anything, if you want there to be. Isn't the fact that one is drawn to ascribe power to a concept indicative of the power of the concept? But I think "potential" is sufficient as a definition.

by vacuity

5/21/2025 at 6:23:02 AM

Becoming powerful might be the easy part

https://www.youtube.com/watch?v=rStL7niR7gs (The Rules for Rulers / CGP Grey)

by marci

5/21/2025 at 7:00:48 AM

That's one of my other favorite things on the internet. The discussion of it is very high quality, too: https://www.youtube.com/watch?v=ILvD7zVN2jo

Getting into a position of power requiring submission to the power hierarchy that grants power is a very keen insight. It means you are subject to all the corruptive forces everyone in those positions of power are also subject to. People will let you into positions of power if you wear their chains.

"Then you must become powerful and choose to use that power for good" is almost directly from CGP Grey's own analysis/those two videos.

Pournelle's iron law of bureaucracy is another way of looking at it: https://www.jerrypournelle.com/reports/jerryp/iron.html

The man in the Arena speech tickles these topics and is unfortunately now more relevant than ever: https://en.wikipedia.org/wiki/Citizenship_in_a_Republic

by hayst4ck

5/20/2025 at 12:59:44 AM

> getting cheated or cooperating with people who act in bad faith is what creates the cheating

That reminds me of some game-theory stuff, a relatively simple "tit-for-tat with forgiveness" approach does pretty well. It matches a lot of our intuition too: Be nice, punish betrayal, but not too disproportionately.

Not the thing I was thinking of, but found this fun little interactive presentation that goes into some other factors/approaches: https://ncase.me/trust/

by Terr_

5/20/2025 at 6:21:54 AM

You linked the same thing as the actual post.

by MIC132

5/20/2025 at 8:42:24 AM

"Tell me you read only comments on HN without telling me you read only comments on HN" )

by divan

5/20/2025 at 7:21:08 PM

1. Skip "animated cartoon..." on mobile

2. Later with desktop from "threads" page see lone comment and try to value-add edit

3. Unlock new remember-that-time-when-you 3AM brain shame

by Terr_

5/21/2025 at 1:23:58 AM

You have perfectly described the downfall of western democracies, who are oh so tolerable.

Even Plato described this already in The Republic.

by martin82

5/21/2025 at 1:12:54 AM

The board game "Diplomacy" teaches lessons like this, also how fairness works even between unequal powers.

by frollogaston

5/20/2025 at 6:25:06 AM

"Si vis pacem, para bellum".

by lmz

5/20/2025 at 10:58:40 AM

OR, you can organize.

The most power-hungry among us often exhibit sociopathic behaviours, and those disproportionately occupy leadership positions. Most good things in our world (democracy, healthcare, welfare) came from building consensus, and weren't gifted by powerful individuals who rose to the top in an effort to bring fire to the masses. To the contrary, when they get their way, welfare and healthcare are cut to give tax breaks to the powerful, and democracies fall to concentrate power more effectively in the hands of the few.

I reject this simplistic Nietzschean analysis of the world. I reject the will to power and the Übermensch. Good societies are built on large groups of people cooperating, not individuals becoming powerful to do good.

by thrance

5/20/2025 at 6:03:19 AM

I admire your bravery, but, do you understand that you risk losing everything in much of the western world for posting such heretical thoughts?

by Nopoint2

5/19/2025 at 7:27:51 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 tiffanyh

5/19/2025 at 8:25:47 PM

Tit-for-Tat with occasional Forgiveness and occasional Defection (abuse of trust) often performs better than pure Tit-For-Tat, especially in the presence of random error. Tit-For-Tat falls into "permanent mutual Defection" tar-pit when playing against a Tit-for-Tat-like opponent that Defects once (perhaps in error) and is non-Forgiving.

Humans are pretty good at repeated-game theory, intuitively.

by gowld

5/19/2025 at 10:06:51 PM

The ncase.me game goes into the forgiveness part

by frollogaston

5/20/2025 at 1:28:22 AM

The success of tit-for-tat is a common misunderstanding; it is only the most successful within the makeup of Axelrod's tournament. The OP explains that the strategy is entirely dependent on the environment, and tit-for-tat may not always be the optimal strategy.

by elliotto

5/20/2025 at 12:13:36 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 gcanyon

5/20/2025 at 1:03:13 AM

I must say this is amazing. The psychology and manipulation makes me realize how poor I am regarding trust even when the other side is pushing for some unconfirmed equilibrium.

In the game I acknowledge that I was aligned to the "Simpleton" strategy (before it was outlined). Looks like simpleton might actually be applicable in a more general sense too which is a little disheartening.

by bjconlan

5/19/2025 at 7:46:34 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 ChicagoBoy11

5/19/2025 at 8:13:06 PM

Another great book on the subject is The Joy of Game Theory by Presh Talwalkar.

by wrboyce

5/19/2025 at 6:33:40 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 netbioserror

5/20/2025 at 2:34:38 PM

Once weakness in those tournaments is that every interaction has the same stakes, so it doesn't model the possibility of "con artists" who behave generally at low stakes, but cheat at high stakes.

by gowld

5/19/2025 at 11:28:59 PM

I remember that as well, but only because it's mentioned in book 8 of The Expanse.

by dfltr

5/19/2025 at 5:53:25 PM

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

by NullHypothesist

5/20/2025 at 3:11:51 AM

Similar - this is where I found out about Komiku's music; I must've heard to thousands of hours of this while writing code

by gota

5/19/2025 at 8:10:14 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 yubblegum

5/19/2025 at 8:21:12 PM

Are you talking about "one-off games" vs "repeated games", or something else?

Repeated games are part of "game theory"

by gowld

5/19/2025 at 9:02:53 PM

Repeated games. Think relationships. Once you have an accurate grasp of the 'character' of your playmate you can approach optimal results.

For example, the character with the flower hat is a 'detective'. We can assume the initial encounter is a coin-toss choice for her and the rest of her choices determined by 'character'. Of course even her first choice is 'in character' (she is 'testing') but if you know her, even if she starts off with a 'cheat' on her first choice, you start off with a 'cooperate'. After that, there is little mystery as to her choices. Or consider the 'grudger'. If for whatever reason you end up choosing 'cheat' once, you know they will never 'forgive' you. etc.

by yubblegum

5/19/2025 at 11:26:41 PM

I don't know if this is the official term for it, but that just sounds like metagaming[1], i.e. incorporating knowledge of the opposing player (or of trends among a group of opposing players) into how you play the game.

[1]: https://en.wikipedia.org/wiki/Metagame#Competitive_gaming

by dfltr

5/19/2025 at 9:15:21 PM

[dead]

by gametheory87

5/20/2025 at 11:08:29 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 krisoft

5/20/2025 at 11:49:11 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 Tsarp

5/20/2025 at 1:40:21 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 fracus

5/20/2025 at 2:05:06 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 drdrek

5/20/2025 at 7:28:46 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 Nopoint2

5/20/2025 at 9:31:05 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 Digit-Al

5/19/2025 at 7:42:47 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 xpe

5/20/2025 at 1:22:12 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 zharknado

5/19/2025 at 9:26:22 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 searine

5/20/2025 at 2:59:16 AM

And the stakes are instant annihilation! so there is no room for mistakes, eliminating almost all other viable positions

by ericrosedev

5/21/2025 at 7:52:40 PM

How the stakes are instant annihilation if the premise itself it's based on the delay of communication? Unless the attack is at the speed of light, you'll still have time to correct the message, right?

by aeve890

5/20/2025 at 11:55:12 AM

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

by pmkary

5/19/2025 at 5:53:15 PM

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

by adi_lancey

5/19/2025 at 7:03:16 PM

The simulation didn't cover the problem that the US is having right now -- intentional miscommunication. Unfortunately, there's a reason some countries employ warehouses full of trolls and propaganda spreaders. If you are losing the "game" spreading chaos will level the playing field. It will take the people of those countries to stop their leadership from acting in bad faith before things improve.

This is also the reason some social media outlets have become dystopian hellscapes.

by daveguy

5/19/2025 at 8:26:58 PM

There's a ncase.me app for that!

https://ncase.itch.io/wbwwb

"WE BECOME WHAT WE BEHOLD a game about news cycles, vicious cycles, infinite cycles"

by gowld

5/19/2025 at 8:44:18 PM

Made me find out I don't dislike the media enough.

by felineflock

5/19/2025 at 10:05:49 PM

https://ncase.me/crowds/ is kinda about this. Not intentional misinformation exactly, just about how ideas like anger are amplified when you have an overly connected social network. There's supposedly a sweet spot.

Also, that's one of my favorite websites ever.

by frollogaston

5/20/2025 at 1:43:26 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 redbell

5/19/2025 at 6:28:20 PM

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

by gowld

5/19/2025 at 9:41:24 PM

very cute!

by badmonster

5/19/2025 at 11:50:40 PM

Now add communication between players to repeated trials.

by derbOac

5/19/2025 at 6:25:49 PM

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

by clueless

5/19/2025 at 8:00:41 PM

The implicit in your q is a negation of the notion of 'social classes'. If you accept the notion of social class (in the political/economical sense) the possibility remains that it is 'theatre' to hoist "authoritarianism" globally over the under classes.

by yubblegum

5/20/2025 at 8:42:01 AM

> more like the rest of the world, more authoritarian

I don't think these are equivalent.

by Peritract