Toward Optimal LLM Alignments Using Two-Player Games
This work addresses the challenge of comprehensive prompt collection for LLM alignment, offering a novel iterative method that could improve safety and robustness, though it appears incremental as it builds on existing RLHF frameworks.
The paper tackles the problem of limited prompt coverage in LLM alignment by proposing a two-agent game framework where an adversarial agent generates prompts to expose weaknesses and a defensive agent improves its responses, theoretically converging to a Nash Equilibrium and experimentally showing enhanced generalization in safety scenarios.
The standard Reinforcement Learning from Human Feedback (RLHF) framework primarily focuses on optimizing the performance of large language models using pre-collected prompts. However, collecting prompts that provide comprehensive coverage is both tedious and challenging, and often fails to include scenarios that LLMs need to improve on the most. In this paper, we investigate alignment through the lens of two-agent games, involving iterative interactions between an adversarial and a defensive agent. The adversarial agent's task at each step is to generate prompts that expose the weakness of the defensive agent. In return, the defensive agent seeks to improve its responses to these newly identified prompts it struggled with, based on feedback from the reward model. We theoretically demonstrate that this iterative reinforcement learning optimization converges to a Nash Equilibrium for the game induced by the agents. Experimental results in safety scenarios demonstrate that learning in such a competitive environment not only fully trains agents but also leads to policies with enhanced generalization capabilities for both adversarial and defensive agents.