Multi-agent artificial intelligence research promises a path to develop intelligent technologies that are more human-like and more human-compatible than those produced by "solipsistic" approaches, which do not consider interactions between agents. Melting Pot is a research tool developed to facilitate work on multi-agent artificial intelligence, and provides an evaluation protocol that measures generalization to novel social partners in a set of canonical test scenarios. Each scenario pairs a physical environment (a "substrate") with a reference set of co-players (a "background population"), to create a social situation with substantial interdependence between the individuals involved. For instance, some scenarios were inspired by institutional-economics-based accounts of natural resource management and public-good-provision dilemmas. Others were inspired by considerations from evolutionary biology, game theory, and artificial life. Melting Pot aims to cover a maximally diverse set of interdependencies and incentives. It includes the commonly-studied extreme cases of perfectly-competitive (zero-sum) motivations and perfectly-cooperative (shared-reward) motivations, but does not stop with them. As in real-life, a clear majority of scenarios in Melting Pot have mixed incentives. They are neither purely competitive nor purely cooperative and thus demand successful agents be able to navigate the resulting ambiguity. Here we describe Melting Pot 2.0, which revises and expands on Melting Pot. We also introduce support for scenarios with asymmetric roles, and explain how to integrate them into the evaluation protocol. This report also contains: (1) details of all substrates and scenarios; (2) a complete description of all baseline algorithms and results. Our intention is for it to serve as a reference for researchers using Melting Pot 2.0.

研究多层合作研究中的一个关键挑战是不仅需要有效合作的个人代理，而且需要与谁合作。当其他代理人隐藏的情况下，可能是错误的动机和目标时，这在局势中特别关键。社交扣除游戏提供途径来研究个人如何学习如何综合有关其他人的潜在不可靠的信息，并阐明其真正的动机。在这项工作中，我们展示了隐藏的议程，这是一个双队的社交扣除游戏，为在未知团队对齐的情况下学习学习代理的2D环境。环境承认两支球队的丰富战略。在隐藏议程中培训的强化学习代理表明，代理商可以学习各种行为，包括合作和投票，而无需以自然语言沟通。