Dominated Strategies

Game Theory · Axiom Academy

Unit 2 - Dominance and Nash Equilibrium 1. Strictly Dominated Strategies A strategy is strictly dominated if there exists another strategy that always gives a higher payoff, regardless of what the opponent does. In the payoff matrix below, we'll identify Player 1's strictly dominated strategy. Watch as we compare the payoffs for each strategy across all possible opponent choices. 2. Weakly Dominated Strategies A strategy is weakly dominated if there exists another strategy that gives at least as high a payoff in all cases, and a strictly higher payoff in at least one case. The difference from strict dominance: the dominating strategy is sometimes equal to the dominated strategy, but never worse. Let's see an example where Strategy B weakly dominates Strategy C. When analyzing a game, we systematically eliminate dominated strategies by "crossing them out" of the payoff matrix. This simplifies the game and reveals the strategies that rational players might actually use. The Logic: If there's always a better option, don't use the dominated strategy. This is a fundamental rationality assumption in game theory.

This is the written version of the interactive lesson above. See the full Game Theory course.