In Bayesian games, players have private information about their type that influences their payoffs and actions. Each player knows their own type but not others' types, which are drawn from a prior distribution. Strategies specify actions for each type, and players choose actions to maximize their expected payoff given beliefs about others' types and strategies. An example is a take-it-or-leave-it offer game where buyers and sellers have private values drawn from a uniform distribution; buyers shade offers to one-half their value to balance acceptance chance against payoff. Incomplete information reduces efficiency as trade requires buyer value exceeds twice seller value.