In automata-theoretic verification, fair simulation is a sufficient condition for trace inclusion. The two notions coincide if the specification automaton is history-deterministic (also called "good-for-games"). History-determinism is nondeterminism that can be resolved by remembering the past, without need for guessing the future. History-determinism is a natural automaton- and game-theoretic concept that can replace determinism for many verification and synthesis questions.