Social-ProtocolsThe Prisoner's Dilemma, Tit for Tat, and how cooperation scalesIn the Prisoner’s Dilemma, two players who each chase a private gain can both end up worse off.Axelrod ran a tournament where computer programs (full strategies) competed against each other. Each entry played a long series against every other program; strategies were ranked by total score, not by one lucky match.Tit for Tat (cooperate first, then mirror the last move) topped those tables: nice, forgiving, clear, and don’t be a pushover (retaliatory).If moves are noisy (random slips), Tit for Tat can lock into long punishment chains. More forgiving rules (for example Tit for Two Tats) blunt that.📄 Read the article