Preparation

A product set of pure strategies is a prep set (‘prep’ is short for ‘preparation’) if it contains at least one best reply to any consistent belief that a player may have about the strategic behavior of his opponents. Minimal prep sets are shown to exist in a class of strategic games satisfying minor topological conditions. The concept of minimal prep sets is compared with (pure and mixed) Nash equilibria, rationalizability, minimal curb sets, and persistent retracts.