This entry explains the payoff structure that makes defection individually attractive while mutual cooperation would improve both players’ outcomes. It explores variants involving asymmetry, more players, repeated interactions, and interpretations of rational choice. The formal structure matters more than the original story about prisoners.
A payoff table describes the preferences stipulated for the players, not a discovery that every person values only material gain. A concern for others could change the relevant ranking and therefore the game. Before applying the model, check whether each player really prefers defection under either choice by the other. If that condition fails, the situation may still involve conflict or coordination, but the argument for the standard dilemma no longer carries over unchanged.