HAI Seminar: Code World Models for General Game Playing

HAI Seminar: Code World Models for General Game Playing

🎙 Wolfgang Lehrach 👥 34K 📅 June 5, 2026 ⏱ 50 min 👁 278 📄 expert opinion 🧭 2026-08-03
Available in: English (current) Français

Keywords

code world modelsLLMgame playingMonte Carlo Tree Searchreinforcement learning

Summary

In this HAI Seminar, Wolfgang Lehrach from DeepMind presents two approaches to improve AI game playing using large language models (LLMs). The first approach, Code World Models (CWMs), involves using LLMs to translate natural-language game rules and trajectories into executable Python code that simulates the game environment. This code is then used with planning algorithms like Monte Carlo Tree Search (MCTS) or reinforcement learning to make decisions. The second approach, a hybrid system, combines LLMs with synthesized code in an online setting, where the LLM and code work together to select actions. Lehrach argues that these methods outperform direct LLM policy generation and code-as-policy approaches, especially for complex or novel games. He discusses the challenges of ambiguity in natural language rules and the benefits of using code as a world model, which provides rich feedback for optimization. The talk also covers extensions to stochastic and partially observable games, and highlights the importance of consistency between different representations (rules, trajectories, code). The presentation includes a Q&A session.

166 words

Critical Evaluation

The talk provides a compelling argument for using code world models over direct LLM policy generation. Lehrach clearly explains the limitations of LLMs as policies, such as poor performance on novel games and high computational cost of fine-tuning. The proposed method of synthesizing executable code from rules and trajectories is well-motivated, leveraging the strengths of LLMs in code generation and the interpretability of symbolic code. The use of unit tests derived from trajectories is a clever way to validate the synthesized model. The talk also addresses the scalability issue of code-as-policy, which is a significant advantage. However, the presentation is somewhat high-level, with limited technical details on the implementation and evaluation. The speaker mentions published papers but does not provide specific results or comparisons. The hybrid approach is introduced but not deeply explored. The Q&A session, though not transcribed, likely addressed some of these gaps. Overall, the talk is informative and presents a promising direction for research, but it would benefit from more concrete evidence and a deeper dive into the methodology. The title accurately reflects the content, and the talk is suitable for an audience with some background in AI and game playing.

194 words

Title / Content Match

The title accurately reflects the content: the talk focuses on code world models for general game playing.

Quality & Reliability

8/10

Presentation by a DeepMind research scientist at Stanford HAI, describing published research (NeurIPS, ICLR). The talk is technical, with clear methodology and references to prior work. However, it is a seminar talk, not a peer-reviewed paper, and some details are simplified.

Key Moments

Cited Sources

  • Code World Models (paper) — Mentioned as published at NeurIPS and ICLR
  • Hybrid system (paper) — Mentioned as presented at ICLR workshop
  • World Coder — Related work mentioned
  • GIF MCTS — Related work mentioned
  • POMDP coder — Related work mentioned

Concurring Sources

  • World Coder — Related work that also uses code as world models, but limited to deterministic games.
  • GIF MCTS — Another related work on code-based world models.
  • POMDP coder — Extends to partially observable games but requires full observability during training.

Dissenting Sources

  • LLM as policy — Direct LLM policy generation is often used but is shown to be less effective for novel games.
  • Code as policy — Scaling issues with complex games.

Contribution & Novelties

The talk presents a novel approach to general game playing by using LLMs to synthesize executable world models from natural language rules and trajectories. This allows for more accurate reasoning and planning compared to direct LLM policy generation. The method also handles stochastic and partially observable games, extending previous work. The hybrid approach, combining LLM and code, offers a flexible alternative.

Pour aller plus loin :

115 words

Radar Profile

The radar profile shows high scores across all dimensions, indicating a well-rounded and reliable presentation. The talk is technically deep, with good information quality and quantity, and high reliability due to the speaker's expertise and published research.

Reliability 8/10