A tit-for-tat strategy is a strategy in which a player in a repeated game takes the same action as another player in the previous period a strategy in which a player in a repeated game alternates between cooperating and cheating in each period a strategy in which a player in a repeated game chooses to cheat in each period a strategy in which a player in a repeated game randomly chooses cooperating or cheating in each period

The tit-for-tat strategy gained fame when it was famously tested in the 1980s in Robert Axelrod's iterated prisoner's dilemma tournaments. Competing strategies were pitted against each other, and it quickly became clear that the simple, straightforward approach of mirroring opponents’ previous moves fostered cooperation and resulted in better long-term outcomes for all players. The charm of tit-for-tat lies in its clear reciprocity, which turns the game from a short-term battle into a long-term partnership. In real life, tit-for-tat has been observed in various contexts, from diplomacy between nations to business negotiations. For instance, if one company decides to collaborate or extend a favorable deal, the other often follows suit, creating a nurturing environment for mutual benefit. This behavior underscores the importance of trust and cooperation, illustrating that building relationships can lead to more fruitful interactions rather than adversarial standoffs.