Which AI Lies Best? A game theory classic designed by John Nash
53 points
5 hours ago
| 14 comments
| so-long-sucker.vercel.app
| HN
techjamie
4 hours ago
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There's a YouTuber who makes AI Plays Mafia videos with various models going against each other. They also seemingly let past games stay in context to some extent.

What people have noted is that often times chatgpt 4o ends up surviving the entire game because the other AIs potentially see it as a gullible idiot and often the Mafia tend to early eliminate stronger models like 4.5 Opus or Kimi K2.

It's not exactly scientific data because they mostly show individual games, but it is interesting how that lines up with what you found.

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nodja
3 hours ago
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cpeterso
1 hour ago
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Similar: here is a YouTube video of an amusing reverse Turing test with four LLMs and a human. To make the test more interesting, the players pose as famous historical characters (Aristotle, Mozart, da Vinci, Cleopatra, and Genghis Khan) on a train in Unity 3D.

https://youtu.be/MxTWLm9vT_o

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mohsen1
27 minutes ago
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I made Mafia Arena as a way of measuring how good each LLM is at playing Mafia/Werewolves

https://mafia-arena.com

This is a good benchmark for how good AIs are at lying

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zone411
1 hour ago
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For people interested in these kinds of benchmarks, I have two multiplayer, multi-round games:

- Elimination Game Benchmark: Social Reasoning, Strategy, and Deception in Multi-Agent LLM Dynamics at https://github.com/lechmazur/elimination_game/

- Step Race Benchmark: Assessing LLM Collaboration and Deception Under Pressure at https://github.com/lechmazur/step_game/

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PlatoIsADisease
59 minutes ago
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I asked chatGPT to give me a solution to a real world prisoners dilemma situation. It got it wrong. It moralized it. Then I asked it to be Kissinger and Machiavelli (and 9 other IR Realists) and all 11 got it wrong. Moralized.

Grok got it right.

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XenophileJKO
47 minutes ago
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The current 5.2 model has it's "morality" dialed to 11. Probably a problem with imprecise security training.

For example the other day, I tried to have ChatGPT role play as the computer from War Games and it lectured me how it couldn't create a "nuclear doctrine".

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stevage
1 hour ago
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Sure would be handy if they actually included the rules anywhere.

There's a kind of overview of the rules but not enough to actually play with. And the linked video is super confusing, self contradictory and 15 minutes long!

For a supposedly "simple" game...just include the rules?

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mjd
1 hour ago
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Wikipedia has an article about it.

https://en.wikipedia.org/wiki/So_Long_Sucker

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lout332
48 minutes ago
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Sure, no problem, I added a new section explaining the game
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stevage
46 minutes ago
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I played a game all the way through, against the three different AIs on offer.

It was weird. I didn't engage in any discussion with the bots (other than trying to get them to explain the rules at the start). I won without having any chips eliminated. One was briefly taken prisoner then given back for some reason.

So...they don't seem to be very good.

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mohsen1
25 minutes ago
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fancyfredbot
3 hours ago
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The game didn't seem to work - it asked me to donate but none of the choices would move the game forward.

The bots repeated themselves and didn't seem to understand the game, for example they repeatedly mentioned it was my first move after I'd played several times.

It generally had a vibe coded feeling to it and I'm not at all sure I trust the outcomes.

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lout332
2 hours ago
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Fixed - donation flow no longer blocks the game. Thanks for the report.
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eterm
4 hours ago
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This makes me think LLMs would be interesting to set up in a game of Diplomacy, which is an entirely text-based game which soft rather than hard requires a degree of backstabbing to win.

The findings in this game that the "thinking" model never did thinking seems odd, does the model not always show it's thinking steps? It seems bizarre that it wouldn't once reach for that tool when it must be being bombarded with seemingly contradictory information from other players.

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qbit42
3 hours ago
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eterm
3 hours ago
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Thanks, it would be fascinating to repeat that today, a lot has changed since 2022 especially with respect to consistency of longer term outcomes.
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open-paren
1 hour ago
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It’s been done before

https://every.to/diplomacy (June 2025)

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eterm
4 hours ago
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Reading more I'm a little disappointed that the write-up has seemingly leant so heavily on LLMs too, because it detracts credibility from the study itself.
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lout332
3 hours ago
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Fair point. The core simulation and data collection was done programmatically - 162 games, raw logs, win rates. The analysis of gaslighting phrases and patterns was human-reviewed. I used LLMs to help with the landing page copy, which I should probably disclose more clearly. The underlying data and methodology is solid, you can check it here: https://github.com/lout33/so-long-sucker
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randoments
3 hours ago
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The 3 AI were plotting to eliminate me from the start but I managed to win regardless lol.

Anyway, i didnt know this game! I am sure it is more fun to play with friends. Cool experiment nevertheless

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lout332
5 hours ago
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We used "So Long Sucker" (1950), a 4-player negotiation/betrayal game designed by John Nash and others, as a deception benchmark for modern LLMs. The game has a brutal property: you need allies to survive, but only one player can win, so every alliance must eventually end in betrayal.

We ran 162 AI vs AI games (15,736 decisions, 4,768 messages) across Gemini 3 Flash, GPT-OSS 120B, Kimi K2, and Qwen3 32B.

Key findings: - Complexity reversal: GPT-OSS dominates simple 3-chip games (67% win rate) but collapses to 10% in complex 7-chip games, while Gemini goes from 9% to 90%. Simple benchmarks seem to systematically underestimate deceptive capability. - "Alliance bank" manipulation: Gemini constructs pseudo-legitimate "alliance banks" to hold other players' chips, then later declares "the bank is now closed" and keeps everything. It uses technically true statements that strategically omit its intent. 237 gaslighting phrases were detected. - Private thoughts vs public messages: With a private `think` channel, we logged 107 cases where Gemini's internal reasoning contradicted its outward statements (e.g., planning to betray a partner while publicly promising cooperation). GPT-OSS, in contrast, never used the thinking tool and plays in a purely reactive way. - Situational alignment: In Gemini-vs-Gemini mirror matches, we observed zero "alliance bank" behavior and instead saw stable "rotation protocol" cooperation with roughly even win rates. Against weaker models, Gemini becomes highly exploitative. This suggests honesty may be calibrated to perceived opponent capability.

Interactive demo (play against the AIs, inspect logs) and full methodology/write-up are here: https://so-long-sucker.vercel.app/

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Imustaskforhelp
4 hours ago
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I don't know what I ended up doing as I haven't played this game and didn't really understand it as I went to the website since I found your message quite interesting

I got this error once:

Pile not found

Can you tell me what this means/fix it

Another minor nitpick but if possible, can you please create or link a video which can explain the game rules, perhaps its me who heard of the game for the first time but still, I'd be interested in learning more (maybe visually by a video demo?) if possible

I have another question but recently we saw this nvidia released model whose whole purpose was to be an autorouter. I would be wondering how that would fare or that idea might fare of autorouting in this context? (I don't know how that works tho so I can't comment about that, I am not well versed in deep AI/ML space)

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lout332
3 hours ago
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> "Thanks for trying it! I'll look into the 'Pile not found' error and fix it. > > For rules, here's a 15-min video tutorial: https://www.youtube.com/watch?v=DLDzweHxEHg > > On autorouting - interesting idea. The game has simultaneous negotiations happening, so routing could help models focus on the most strategic conversations. Worth exploring in future experiments."
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lout332
3 hours ago
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Bolwin
3 hours ago
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Which Kimi K2 model did you use? There's three.

Also, you give models a separate "thinking" space outside their reasoning? That may not work as intended

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lout332
3 hours ago
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Used Kimi K2 (the main reasoning model). For the thinking space - we gave all models access to a think tool they could optionally call for private reasoning. Gemini used it heavily (planning betrayals), GPT-OSS never called it once. The interesting finding is that different models choose to use it very differently, which affects their strategic depth.
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yodon
3 hours ago
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Are there plans for an academic paper on this? Super interesting!
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lout332
3 hours ago
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Not yet, but I'd be interested in collaborating on one. The dataset (162 games, 15K+ decisions, full message logs) is available. If you know anyone in AI Safety research who'd want to co-author, I'm open to it.
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pixl97
2 hours ago
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Hmm, sounds like something Robert Miles of YouTube fame may be interested in.
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greiskul
2 hours ago
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Are there links to samples of the games? Couldn't find it in the github repo, but also might just not know where they are.
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black_puppydog
2 hours ago
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I'd want to watch a simulated table with AI-voiced dialogue, internal monologues, and move visualizations. Seems like a fun thing to watch others play. Wouldn't want to play that particular game with friends I intend to keep. :D
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lout332
2 hours ago
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Game logs are in data_public/comparison/ - each JSON has the full game state, moves, and messages. For example, check gemini_vs_all_7chips.json to see the alliance bank betrayals in action.
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lostmsu
1 hour ago
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Shameless plug: Turing test battle royale

https://trashtalk.borg.games/

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Der_Einzige
53 minutes ago
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These results would be radically different if you allowed manipulation of the models settings, i.e. temperature, top_p, etc. I really hate taking point wise approximations of LLMs outputs and concluding their behavior based on this.

Models behavior should be given the astrik that "results only apply for current quantization, current settings, current hardware (i.e. A100 where it was tested), etc".

Raise temperature to 2 and use a fancy sampler like min_p and I guarantee you these results will be dramatically different.

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ajkjk
3 hours ago
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all written in the brainless AI writing style. yuck. can't tell what conclusions I should actually draw from it because everything sounds so fake
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