The paper suggests a non-cooperative simultaneous game, with a number of potential deviators is a parameter of the game. A definition of the game embeds mechanism design. The game has an equilibrium in mixed strategies. The equilibrium encompasses intra and inter group externalities and individual payoffs that make it different from a strong Nash, coalition-proof equilibrium and some other equilibrium concepts. We offer a non-cooperative stability criterion to describe a robustness of an equilibrium strategy profile to an increase in a number of deviators. The criterium may serve as a way to measure trust for the equilibrium in terms of a number of potential deviators.