There can be some globle state, and some agent state .
Cooperative multi-agent RL often requires decentralised policies, which limit the agents’ ability to coordinate their behaviour .
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 de Witt, Christian Schroeder, Jakob Foerster, Gregory Farquhar, Philip Torr, Wendelin Boehmer, and Shimon Whiteson. “Multi-agent common knowledge reinforcement learning.” In Advances in Neural Information Processing Systems, pp. 9927-9939. 2019.