Perfect recall (game theory)

In game theory, perfect recall is a property of players within extensive-form games, introduced by Harold W. Kuhn in 1953. it describes a player's ability to remember their past actions and the information they possessed at previous decision points. For example, in a simplified card game where a player makes multiple betting rounds, perfect recall means they remember their own previous bets and the cards they've seen. Essentially, it indicates that a player does not "forget" relevant information acquired during the game.

It is important to distinguish perfect recall from perfect information. While perfect information means all players know all previous actions of all players, perfect recall means a player remembers their own past actions and knowledge.