Moves You Should Never Play (Dominated Strategies)

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Why this matters

If a strategy is worse than another no matter what anyone else does, a rational player never plays it. This is the closest thing to a free lunch in game theory — you can eliminate dominated strategies without any assumptions about what the other player believes. Dominant strategies, when they exist, are even cleaner: there is literally no argument about what to play. Getting fluent at spotting dominance, strict vs weak, is how you chop down a 10x10 game to something you can reason about.

Demo

Strategy $s_i$ is strictly dominated by $s_i'$ if $s_i'$ does strictly better than against every strategy profile of the others:

Moves You Should Never Play (Dominated Strategies)

Why this matters

Demo

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References