Cooperation

Repeated games and tit for tat

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Repeated play can make cooperation rational: the shadow of the future.
• Tit for Tat: nice, retaliatory, forgiving and clear. It won Axelrod’s tournaments.
• With a known final round, the incentive to defect at the end returns.

Steps

1. Play it again
2. Axelrod’s tournaments
3. Cooperation on a grid
4. Why repetition helps
5. Noisy moves
6. Patience pays
7. Last round