A strategy is dominated if, regardless of what any other players do, the strategy earns a player a smaller payoff than some other strategy.
Hence, a strategy is dominated if it is always better to play some other strategy, regardless of what opponents may do.
If a player has a dominant strategy than all others are dominated, but the converse is not always true.
A strictly dominant strategy is always played in equilibrium, and thus strictly dominated strategies never are.
For example, in the prisoner's dilemma, each player has a dominated strategy.
Equilibria exist with weakly dominated strategies, however.

updated: 22 August 2006

HOW TO CITE THIS ENTRY

- To learn more:
- See news articles on normal-form games.
- Play the repeated prisoner's dilemma on the applets page.
- The Prisoner's dilemma is featured in many movies.