Prisoner’s Dilemma
Etymology
The game was formalized by Merrill Flood and Melvin Dresher at the RAND Corporation in 1950; mathematician Albert W. Tucker supplied the memorable framing of two arrested accomplices deciding whether to betray each other. The narrative packaging gave the abstract payoff matrix its lasting name.
noun phrase · /PRIZ-uh-nerz dih-LEM-uh/
A situation in which two parties, each acting in their own rational self-interest, end up worse off than if they had cooperated.
What it names
The canonical model of why cooperation fails even when everyone would gain from it — a lens for arms races, price wars, climate stalemates, and any standoff where trust is the missing ingredient.
Example
The two rival gas stations are stuck in a prisoner’s dilemma — neither dares stop the price war first.
Related idea
It is a specific two-player instance of a non-zero-sum game; unlike a pure zero-sum clash, mutual cooperation would leave both better off, which is exactly what makes the failure tragic.