## Quick Reference

In decision theory and game theory, an alternative or strategy (2) that, in every contingency that might arise, yields a payoff at least as good as the payoff from any other available alternative or strategy and a strictly better payoff in at least one. A dominant strategy is *strongly dominant* if it yields a strictly better payoff than any other alternative or strategy in every possible contingency, otherwise it is *weakly dominant*. An alternative or strategy that is not dominated by any other is an *admissible alternative/strategy*, and in a decision problem in which a dominant strategy exists, another alternative or strategy that is not dominant is a *dominated alternative/strategy* or an *inadmissible alternative/strategy*. It is generally agreed that a rational decision maker or player will never deliberately choose a dominated alternative or strategy, but this principle appears counter-intuitive to some people in puzzles such as Newcomb's problem and the Prisoner's Dilemma game. Also called a *dominating alternative/strategy*. See also prospect theory, sure-thing principle.

*Subjects:*
Psychology.