Tit for Tat

Tit for tat is a game-theory strategy subject to a payoff matrix like that of a prisoner’s dilemma. Tit for tat was introduced by Anatol Rapoport, who developed a strategy in which each participant in an iterated prisoner’s dilemma follows a course of action consistent with his opponent’s previous turn. For example, if provoked, a player subsequently responds with retaliation; if unprovoked, the player cooperates.