It begins to cooperate, and then play what its opponent played in the last move. It cooperates until the opponent has defected, after that move it always defects. First move is considered to be equality. It cooperates if and only if both players opted for the same choice in the previous move. Cooperates except if opponent has defected at least one time in the two previous move.
First move is considered to be equality.
Y. Leborgne , undergraduate student, is involved in some mathematicals research on a variation of the Iterated Prisoner's Dilemma, we have set up. Here are an extensive list of the papers written, and published by members of the team. They mainly present our ideas and results about the cooperation through the IPD model. An automatically generated complete bibliography of all papers or books we have is available here . An annotated bibliography on the Evolution of Cooperation has been set up by Robert Axelrod and Lisa D'Ambrosio , and is available here .