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I’ve been working on board game ai lately. Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look

I’ve been working on board game ai lately. Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look 50 moves ahead’. This is how chess engines work and how all good turn based game ai works. I’ve tried throwing masses of game state data at latest models in pytorch. Unusable. It Makes really dumb moves. In fact one big issue is that it often suggests invalid moves and the best way to avoid this is to implement the board game logic in full to validate it. At which point, why don’t i just do the above scan ahead X moves since i have to do the hard parts of manually building the world model anyway? One area where current ai is helping is on the heuristics themselves for evaluating best moves when scanning ahead. You can input various game states and whether the player won the game or not in the end to train the values of the heuristics. You still need to implement the world model and look ahead to use those heuristics though! When you hear of neural networks being used for go or chess this is where they are used. You still need to build the world model and brute force scan ahead. One path i do want to try more: In theory coding assistants should be able to read rulebooks and dynamically generate code to represent those rules. If you can do that part the rest should be easy. Ie. it could be possible to throw rulebooks at ai and it play the game. It would generate a world model from the rulebook via coding assistants and scan ahead more moves than humanly possible using that world model, evaluating to some heuristics that would need to be trained through trial and error. Of course coding assistants aren’t at a point where you can throw rulebooks at them to generate an internal representation of game states. I should know. I just spent weeks building the game model even with a coding assistant.

coeneedell 1y ago
IIRC the rules system for magic the gathering: Arena is generated by a sort of compiler fed the rules. You might not even need a modern coding assistant to build out something reasonable in a DSL that is perfect, then have people (or an LLM after fine tuning) transforms rule books into the DSL.
- Crespyl 1y ago
  They have an interesting write up here: https://magic.wizards.com/en/news/mtg-arena/on-whiteboards-naps-and-living-breakthrough https://magic.wizards.com/en/news/mtg-arena/on-whiteboards-n... There's a lisp variant involved, and IIRC even a parser that reads the card text to auto-generate the rules code for most of the cards.
  - fennecbutt 1y ago
    Tho tbf there are plenty of cards with what are essentially footnotes. They say reading the card explains the card but that's not always the case, sometimes there's nuance because mtg has so many fucking crazy interactions and the whole stack thing. I haven't played in a month or two but now I'm getting that itch again aha. When's bloomburrow 2, enough of this UB crap.
GaggiX 1y ago
>This is how chess engines work All strongest chess engine have at least one neural network to evaluate positions, including Stockfish, and this impact the searching window. >how all good turn based game ai works That's not really true, just think of Go.
- skywhopper 1y ago
  ??? Chess engines and Go engines have as a baseline a world model of the state of the game and what moves are legal.
  - GaggiX 1y ago
    >Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look 50 moves ahead’. This is how chess engines work and how all good turn based game ai works. Just read the parent comment.
smokel 1y ago
You probably know this, but things heavily depend on the type of board game you are trying to solve. In Go, for instance, it does not help much to look 50 moves ahead. The complexity is way too high for this to be feasible, and determining who's ahead is far from trivial. It's in these situations where modern AI (reinforcement learning, deep neural networks) helps tremendously. Also note that nobody said that using AI is easy.
- AnotherGoodName 1y ago
  Alphago (and stockfish that another commenter mentioned) still has to search ahead using a world model. The AI training just helps with the heuristics for pruning and evaluation of that search. The big fundamental blocker to a generic ‘can play any game’ ai is the manual implementation of the world model. If you read the alphago paper you’ll see ‘we started with nothing but an implementation of the game rules’. That’s the part we’re missing. It’s done by humans.
  - smokel 1y ago
    Implementing a world model seems to be mostly solved by LLMs. Finding one that can be evaluated fast enough to actually solve games is extremely hard, for humans and AI alike.
    - skywhopper 1y ago
      What are you talking about?
      - smokel 1y ago
        Optimization is harder than writing out the rules of a game. For most board games, it is trivial to describe all possible next states, but it is not at all trivial to search through all of these to find the best action to take.
  - moyix 1y ago
    Note that MuZero did better than AlphaGo, without access to preprogrammed rules: https://en.wikipedia.org/wiki/MuZero https://en.wikipedia.org/wiki/MuZero
jjk7 1y ago
Interesting the parallels between LLM development and psychology & spirituality. To have a true thinking, you need an internal adversary challenging thoughts and beliefs. To look 50 moves ahead, you need to simulate the adversary's moves... Duality
daxfohl 1y ago
Yeah, I can't even get them to retain a simple state. I've tried having them run a maze, but instead of giving them the whole maze up front, I have them move one step at a time, tell them which directions are open from that square and ask for the next move, etc. After a few moves they get hopelessly lost and just start wandering back and forth in a loop. Even when I prompt them explicitly to serialize a state representation of the maze after each step, and even if I prune the old context so they don't get tripped up on old state representations, they still get flustered and corrupt the state or lose track of things eventually. They get the concept: if I explain the challenge and ask to write a program to solve such a maze step-by-step like that, they can do that successfully first-try! But maintaining it internally, they still seem to struggle.
- warrenm 1y ago
  >I've tried having them run a maze, but instead of giving them the whole maze up front, I have them move one step at a time, tell them which directions are open from that square and ask for the next move, etc. Presuming these are 'typical' mazes (like you find in a garden or local corn field in late fall), why not have the bot run the known-correct solving algorithm (or its mirror)?
  - daxfohl 1y ago
    Like I said, they can implement the algorithm to solve it, but when forced to maintain the state themselves, either internally or explicitly in the context, they are unable to do so and get lost. Similarly if you ask to write a Sudoku solver, they have no problem. And if you ask an online model to solve a sudoku, it'll write a sudoku solver in the background and use that to solve it. But (at least the last time I tried, a year ago), if you ask to solve step-by-step using pure reasoning without writing a program, they start spewing out all kinds of nonsense (but humorously cheat: they'll still spit out the correct answer at the end).
    - adventured 1y ago
      So if you push eg Claude Sonnet 4 or Opus 4.1 into a maze scenario, and have it record its own pathing as it goes, and then refresh and feed the next Claude the progress so far, would that solve for the inability to maintain long duration context in such maze cases? I make Claude do that on every project. I call them Notes for Future Claude and have it write notes for itself because of how quickly context accuracy erodes. It tends to write rather amusing notes to itself in my experience.
red75prime 1y ago
It would be nice if you could train a decent model on a $1000 (or so) budget, but for now it seems unlikely.
bubblyworld 1y ago
Something to consider is that while it's really hard to implement a decent NN-based algorithm like AlphaZero for your game, you get the benefit that model checkpoints give you a range of skill levels to play against as you train it. Handicapping traditional tree search produces really terrible results, imo. It's common for weak chess engines to be weak for stupid reasons (they just hang pieces, make random unnatural moves, miss blatant threats etc). Playing weak versions of Leela chess really "feels" like a (bad) human opponent by contrast. Maybe the juice isn't worth the squeeze. It's definitely a ton of work to get right.
robertlagrant 1y ago
How does this experience translate to non-turn based games? Alphastar presumably is doing something other than searching all the possible moves. Why would whatever it does not translate to turn-based?
deepsquirrelnet 1y ago
> I’ve tried throwing masses of game state data at latest models in pytorch. Unusable. It Makes really dumb moves. In fact one big issue is that it often suggests invalid moves and the best way to avoid this is to implement the board game logic in full to validate it. It sounds like you need RL. You could try setting up some reward functions with evaluators. I’m not sure what your architecture is, but something to try.
PeterStuer 1y ago
"Elephants don't play chess" ;) You have a tiny, completely known, deterministic rule based 'world'. 'Reasoning' forwards for that is trivial. Now try your approach for much more 'fuzzy', incomletely and ill defined environments, e.g. natural language production, and watch it go down in flames. Different problems need different solutions. While current frontier llm's show surprising results in emergent shallow and linguistic reasoning, they are far away from deep abstract logical reasoning. A sota theorem prover otoh, can excel at that, but can still struggle to produce a coherent sentence. I think most have always agreed that for certain tasks, an abstraction over which one can 'reason' is required. People differ in opinion over wether this faculty is to be 'crafted' in or wether it is possible to have it emerge implicitly and more robust from observations and interactions. https://people.csail.mit.edu/brooks/papers/elephants.pdf https://people.csail.mit.edu/brooks/papers/elephants.pdf
- AnotherGoodName 1y ago
  What seems bizarre though is that the language problem was fully solved first (where fully solved means AI can learn it through pure observation with no human intervention at all). As in language today is learnt by basically throwing raw data at an LLM. Board games such as chess still require a human to manually build a world model for the state space search to work on. They are indeed totally different problems but it's still shocking to me which one was fully solved first.
  - tim333 1y ago
    >Board games such as chess still require a human to manually build a world model for the state space search to work on That's not so. Deepmind MuZero can learn most board games without even being told the rules.
ChaitanyaSai 1y ago
Interesting! Documenting this anywhere?
MachineBurning 1y ago
> Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look 50 moves ahead’. This is how chess engines work and how all good turn based game ai works. For board games this is mostly true. For turn based games in general, it is not. It's certainly not true to say "all good turn based game ai" works like this. Turn based games where multiple "moves" are allowed per turn can very quickly have far too many branches to look ahead more than a very small number of turns. On board games you might have something like Warhammer, or Blood Bowl where there are many possible actions and order of actions within a turn matters. For computer games you may Screeps [2] or the Lux multi-agent AI competitions [3] which both have multiple "units" per player, where each unit may have multiple possible actions. You can easily reach a combinatorial explosion where any attempt at modeling future states of the world fails and you have to fall back on pure heuristics. [1]https://en.wikipedia.org/wiki/Blood_Bowl https://en.wikipedia.org/wiki/Blood_Bowl [2]https://screeps.com/ https://screeps.com/ [3]https://www.kaggle.com/competitions/lux-ai-season-2 https://www.kaggle.com/competitions/lux-ai-season-2

coeneedell 1y ago

IIRC the rules system for magic the gathering: Arena is generated by a sort of compiler fed the rules. You might not even need a modern coding assistant to build out something reasonable in a DSL that is perfect, then have people (or an LLM after fine tuning) transforms rule books into the DSL.

Crespyl 1y ago
They have an interesting write up here: https://magic.wizards.com/en/news/mtg-arena/on-whiteboards-naps-and-living-breakthrough https://magic.wizards.com/en/news/mtg-arena/on-whiteboards-n... There's a lisp variant involved, and IIRC even a parser that reads the card text to auto-generate the rules code for most of the cards.
- fennecbutt 1y ago
  Tho tbf there are plenty of cards with what are essentially footnotes. They say reading the card explains the card but that's not always the case, sometimes there's nuance because mtg has so many fucking crazy interactions and the whole stack thing. I haven't played in a month or two but now I'm getting that itch again aha. When's bloomburrow 2, enough of this UB crap.

GaggiX 1y ago

>This is how chess engines work All strongest chess engine have at least one neural network to evaluate positions, including Stockfish, and this impact the searching window. >how all good turn based game ai works That's not really true, just think of Go.

skywhopper 1y ago
??? Chess engines and Go engines have as a baseline a world model of the state of the game and what moves are legal.
- GaggiX 1y ago
  >Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look 50 moves ahead’. This is how chess engines work and how all good turn based game ai works. Just read the parent comment.

smokel 1y ago

You probably know this, but things heavily depend on the type of board game you are trying to solve. In Go, for instance, it does not help much to look 50 moves ahead. The complexity is way too high for this to be feasible, and determining who's ahead is far from trivial. It's in these situations where modern AI (reinforcement learning, deep neural networks) helps tremendously. Also note that nobody said that using AI is easy.

AnotherGoodName 1y ago
Alphago (and stockfish that another commenter mentioned) still has to search ahead using a world model. The AI training just helps with the heuristics for pruning and evaluation of that search. The big fundamental blocker to a generic ‘can play any game’ ai is the manual implementation of the world model. If you read the alphago paper you’ll see ‘we started with nothing but an implementation of the game rules’. That’s the part we’re missing. It’s done by humans.
- smokel 1y ago
  Implementing a world model seems to be mostly solved by LLMs. Finding one that can be evaluated fast enough to actually solve games is extremely hard, for humans and AI alike.
  - skywhopper 1y ago
    What are you talking about?
    - smokel 1y ago
      Optimization is harder than writing out the rules of a game. For most board games, it is trivial to describe all possible next states, but it is not at all trivial to search through all of these to find the best action to take.
- moyix 1y ago
  Note that MuZero did better than AlphaGo, without access to preprogrammed rules: https://en.wikipedia.org/wiki/MuZero https://en.wikipedia.org/wiki/MuZero

jjk7 1y ago

Interesting the parallels between LLM development and psychology & spirituality. To have a true thinking, you need an internal adversary challenging thoughts and beliefs. To look 50 moves ahead, you need to simulate the adversary's moves... Duality

daxfohl 1y ago

Yeah, I can't even get them to retain a simple state. I've tried having them run a maze, but instead of giving them the whole maze up front, I have them move one step at a time, tell them which directions are open from that square and ask for the next move, etc. After a few moves they get hopelessly lost and just start wandering back and forth in a loop. Even when I prompt them explicitly to serialize a state representation of the maze after each step, and even if I prune the old context so they don't get tripped up on old state representations, they still get flustered and corrupt the state or lose track of things eventually. They get the concept: if I explain the challenge and ask to write a program to solve such a maze step-by-step like that, they can do that successfully first-try! But maintaining it internally, they still seem to struggle.

warrenm 1y ago
>I've tried having them run a maze, but instead of giving them the whole maze up front, I have them move one step at a time, tell them which directions are open from that square and ask for the next move, etc. Presuming these are 'typical' mazes (like you find in a garden or local corn field in late fall), why not have the bot run the known-correct solving algorithm (or its mirror)?
- daxfohl 1y ago
  Like I said, they can implement the algorithm to solve it, but when forced to maintain the state themselves, either internally or explicitly in the context, they are unable to do so and get lost. Similarly if you ask to write a Sudoku solver, they have no problem. And if you ask an online model to solve a sudoku, it'll write a sudoku solver in the background and use that to solve it. But (at least the last time I tried, a year ago), if you ask to solve step-by-step using pure reasoning without writing a program, they start spewing out all kinds of nonsense (but humorously cheat: they'll still spit out the correct answer at the end).
  - adventured 1y ago
    So if you push eg Claude Sonnet 4 or Opus 4.1 into a maze scenario, and have it record its own pathing as it goes, and then refresh and feed the next Claude the progress so far, would that solve for the inability to maintain long duration context in such maze cases? I make Claude do that on every project. I call them Notes for Future Claude and have it write notes for itself because of how quickly context accuracy erodes. It tends to write rather amusing notes to itself in my experience.

red75prime 1y ago

It would be nice if you could train a decent model on a $1000 (or so) budget, but for now it seems unlikely.

bubblyworld 1y ago

Something to consider is that while it's really hard to implement a decent NN-based algorithm like AlphaZero for your game, you get the benefit that model checkpoints give you a range of skill levels to play against as you train it. Handicapping traditional tree search produces really terrible results, imo. It's common for weak chess engines to be weak for stupid reasons (they just hang pieces, make random unnatural moves, miss blatant threats etc). Playing weak versions of Leela chess really "feels" like a (bad) human opponent by contrast. Maybe the juice isn't worth the squeeze. It's definitely a ton of work to get right.

robertlagrant 1y ago

How does this experience translate to non-turn based games? Alphastar presumably is doing something other than searching all the possible moves. Why would whatever it does not translate to turn-based?

deepsquirrelnet 1y ago

> I’ve tried throwing masses of game state data at latest models in pytorch. Unusable. It Makes really dumb moves. In fact one big issue is that it often suggests invalid moves and the best way to avoid this is to implement the board game logic in full to validate it. It sounds like you need RL. You could try setting up some reward functions with evaluators. I’m not sure what your architecture is, but something to try.

PeterStuer 1y ago

"Elephants don't play chess" ;) You have a tiny, completely known, deterministic rule based 'world'. 'Reasoning' forwards for that is trivial. Now try your approach for much more 'fuzzy', incomletely and ill defined environments, e.g. natural language production, and watch it go down in flames. Different problems need different solutions. While current frontier llm's show surprising results in emergent shallow and linguistic reasoning, they are far away from deep abstract logical reasoning. A sota theorem prover otoh, can excel at that, but can still struggle to produce a coherent sentence. I think most have always agreed that for certain tasks, an abstraction over which one can 'reason' is required. People differ in opinion over wether this faculty is to be 'crafted' in or wether it is possible to have it emerge implicitly and more robust from observations and interactions. https://people.csail.mit.edu/brooks/papers/elephants.pdf https://people.csail.mit.edu/brooks/papers/elephants.pdf

AnotherGoodName 1y ago
What seems bizarre though is that the language problem was fully solved first (where fully solved means AI can learn it through pure observation with no human intervention at all). As in language today is learnt by basically throwing raw data at an LLM. Board games such as chess still require a human to manually build a world model for the state space search to work on. They are indeed totally different problems but it's still shocking to me which one was fully solved first.
- tim333 1y ago
  >Board games such as chess still require a human to manually build a world model for the state space search to work on That's not so. Deepmind MuZero can learn most board games without even being told the rules.

ChaitanyaSai 1y ago

Interesting! Documenting this anywhere?

MachineBurning 1y ago

> Fwiw nothing beats ‘implement the game logic in full (huge amounts of work) and with pruning on some heuristics look 50 moves ahead’. This is how chess engines work and how all good turn based game ai works. For board games this is mostly true. For turn based games in general, it is not. It's certainly not true to say "all good turn based game ai" works like this. Turn based games where multiple "moves" are allowed per turn can very quickly have far too many branches to look ahead more than a very small number of turns. On board games you might have something like Warhammer, or Blood Bowl where there are many possible actions and order of actions within a turn matters. For computer games you may Screeps [2] or the Lux multi-agent AI competitions [3] which both have multiple "units" per player, where each unit may have multiple possible actions. You can easily reach a combinatorial explosion where any attempt at modeling future states of the world fails and you have to fall back on pure heuristics. [1]https://en.wikipedia.org/wiki/Blood_Bowl https://en.wikipedia.org/wiki/Blood_Bowl [2]https://screeps.com/ https://screeps.com/ [3]https://www.kaggle.com/competitions/lux-ai-season-2 https://www.kaggle.com/competitions/lux-ai-season-2