•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

The** Prisoner'Prisoner's Dilemma** is a well-studied game in game theory, where supposedly rational incentive following leads to both players stabbing each other in the back and being worse off than if they had cooperated.

The ~~"stay silent"~~"stay silent" option is generally called ~~Cooperate,~~**Cooperate**, and the ~~"betray"~~"betray" option is called ~~Defect.~~**Defect**. The only Nash Equilibrium of the ~~Prisoner'~~Prisoner's Dilemma is both players defecting, even though each would prefer the cooperate/cooperate outcome.

Notice that it's only if you treat the other player's decision as completely independent from yours, if the other player defects, then you score higher if you defect as well, whereas if the other player cooperates, you do better by defecting. Hence Nash Equilibrium to defect (at least if the game is to be played only once), and indeed, this is what classical causal decision theory says. And yet—and yet, if only somehow both players could agree to cooperate, they would both do better than if they both defected. If the players are timeless decision agents, or functional decision theory agents, they can.

A popular variant is the Iterated ~~Prisoner'~~Prisoner's Dilemma, where two agents play the ~~Prisoner'~~Prisoner's Dilemma against each other a number of times in a row. A simple and successful strategy is called Tit for Tat - cooperate on the first round, then on subsequent rounds do whatever your opponent did on the last round.

(Stanford Encyclopedia of Philosophy)~~Prisoner'~~Prisoner's dilemma