Antagonistic games

Abstract

Some properties of zero-sum games are extended to different classes of two-person non zero-sum games. The definitions of these classes are based on different notions of antagonism. The notion of almost strictly competitive games introduced by Aumann in 1961, is generalized while keeping the uniqueness of Nash equilibrium payoff. The set of Nash equilibria of a weakly unilaterally competitive game coincides with the set of its saddle points. Some properties are satisfied by the correlated equilibrium payoff of a weakly unilaterally competitive game; and by Nash equilibria of a symmetric weakly unilaterally competitive games.