The Evolution Of Co-operation

Playing The Game

Tit for tat is a highly effective strategy in game theory for the iterated prisoner's dilemma. It was first introduced by Anatol Rapoport in Robert Axelrod's two tournaments, held around 1980. An agent using this strategy will initially co-operate, then respond in kind to an opponent's previous action. If the opponent previously was co-operative, the agent is cooperative. If not, the agent is not.