Game Theory
The mathematical study of strategic decision-making, where your best move depends on what others do. It models competition, cooperation, and conflict.
Origin
Hungarian-American mathematician John von Neumann laid the foundation with his 1928 proof of the minimax theorem for two-person zero-sum games. He and Austrian-American economist Oskar Morgenstern then co-authored Theory of Games and Economic Behavior (1944), published by Princeton University Press, which established the field. John Nash extended it in 1950 with his equilibrium concept for non-zero-sum games, earning the 1994 Nobel Prize.
Everyday Use
Should you undercut a competitor's price or hold firm? Cooperate with a colleague or go it alone? Every time your best choice depends on what someone else does, you're living inside a game-theory scenario — from salary negotiations to splitting a dinner bill to deciding whether to merge in traffic.