The Prisoner's Dilemma

Nash showed that rational players in tension settle at a point where no one can improve by moving alone. In the Prisoner's Dilemma that point is mutual defection — worse for both than cooperation. Understanding why is how you learn to change it.

• —Read a payoff matrix and find the equilibrium.
• —Explain why mutual defection is rational and still bad.
• —Name the three levers that turn defection into cooperation.