Structural Entropy Optimized Communication for Multi-Agent Reinforcement Learning

Communication learning is crucial for complex coordination in multi-agent reinforcement learning (MARL), yet existing methods often struggle with a fundamental dilemma between communication overhead and task performance. Typically designed without theoretical guidance, they produce unstructured and redundant communication graphs, limiting both efficiency and scalability. To address this, we propose Structural Entropy Optimized Communication (SEOC), a framework that directly optimizes inter-agent communication topology using the information-theoretic principle of Structural Entropy. SEOC guides the network to self-organize into a low-entropy state with sparse connectivity and distinct communities, enabling efficient and interpretable decentralized coordination. This is achieved through a unified mechanism that jointly enforces structural order and semantic conciseness, reducing topological complexity via a differentiable structural entropy loss while compressing messages with a node information bottleneck. Experiments on benchmarks such as the StarCraft Multi-Agent Challenge (SMACv2) demonstrate that SEOC significantly outperforms state-of-the-art methods.