Dominant strategy

A strategy is dominant if, regardless of what any other players do, the strategy earns a player a larger payoff than any other. Hence, a strategy is dominant if it is always better than any other strategy, for any profile of other players’ actions.

Depending on whether “better” is defined with weak or strict inequalities, the strategy is termed strictly dominant or weakly dominant. If one strategy is dominant, than all others are dominated. For example, in the prisoner’s dilemma, each player has a dominant strategy.

Source: Shor, Mikhael, “Dominant Strategy,” Dictionary of Game Theory Terms, Game Theory .net, http://www.gametheory.net/dictionary/DominantStrategy.html