Iterated Prisoners Dilemma

An iterated form of the Prisoner's Dilemma, a two-player game of fundamental importance in game theory. Repetition of the game with the same pair of players changes the payoff matrix, favoring long-term cooperation. This topic was explored in the book The Evolution of Cooperation.

In the single-play case, defection is always the preferred strategy. Likewise if the number of remaining plays in the iterated case is disclosed to the players, cooperation ceases to be appealing. For cooperation to remain appealing, the future must be indeterminate for both players.