A strategy is dominated if, no matter what the other players do, the strategy earns a player a smaller payoff than another strategy. Hence, a method is dominated if it's invariably higher to play another strategy, no matter what opponents might do. If a player contains a dominant strategy than all others are dominated, however the converse isn't invariably true. A strictly dominant strategy is usually played in equilibrium, and therefore strictly dominated methods never are. for instance, within the prisoner's dilemma, every player contains a dominated strategy. Equilibria exist with weakly dominated methods, however.