Prisoner’s Dilemma (article)

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.

Begin with the basic two-player table. Identify the ranking of temptation, mutual cooperation, mutual defection, and unilateral cooperation. Only then move to repeated or many-player versions. When applying the model to an everyday example, check whether its incentives really meet those conditions.

Ask what changes the game: monitoring, commitments, future encounters, or different preferences. A strategic equilibrium and a morally justified outcome are distinct judgments. The article supplies tools for understanding incentives; it does not prove that every cooperative problem has one solution or that people must act selfishly.

Try an original example involving two neighbors contributing to a shared garden. Write all four outcomes and include effort as well as enjoyment. Then introduce an agreed maintenance schedule and ask which payoffs it changes. Keep the moral question separate: an arrangement that stabilizes contribution may still distribute work unfairly. Reading the formal account alongside this exercise makes it easier to see which claims concern strategic incentives and which require an additional ethical argument.