Mutual knowledge

Mutual knowledge in game theory is information known by all participatory agents. However, unlike common knowledge, a related topic, mutual knowledge does not require that all agents are aware that this knowledge is mutual. All common knowledge is mutual knowledge, but not all mutual knowledge is common knowledge. Mutual knowledge can arise accidentally, due to a failure to design the game properly, so all players independently discover this mutual knowledge, or deliberately, due to the expected course of the game.