Extensive-Form Correlated Equilibrium: Definition and Computational Complexity

This paper defines the extensive–form correlated equilibrium (EFCE) for extensive games with perfect recall. The EFCE concept extends Aumann's strategic–form correlated equilibrium (CE). Before the game starts, a correlation device generates a move for each information set. This move is recommended to the player only when the player reaches the information set. In two–player perfect–recall extensive games without chance moves, the set of EFCE can be described by a polynomial number of consistency and incentive constraints. Assuming P is not equal to NP, this is not possible for the set of CE, or if the game has chance moves.