The optional prisoner's dilemma (OPD) game models a situation of conflict involving two players in game theory. It can be seen as an extension of the standard prisoner's dilemma game, where players have the option to "reject the deal", that is, to abstain from playing the game. This type of game can be used as a model for a number of real world situations in which agents are afforded the third option of abstaining from a game interaction such as an election.

The structure of the optional prisoner's dilemma can be generalized from the standard prisoner's dilemma game setting. In this way, suppose that the two players are represented by the colors, red and blue, and that each player chooses to "Cooperate", "Defect" or "Abstain".

The payoff matrix for the game is shown below:

The following condition must hold for the payoffs:

T > R > L > P > S