In this note a concept of a cooperative solution of an n-person positional differential game is proposed. The setting of the game assumes that the cooperative solution is not compulsory for the players in the sense that particular players, as well as coalitions of players, have a right to deviate from this solution in the process of the game. In order to prevent such deviations it is necessary to make them disadvantageous for the deviating players. The proposed solution is stable under deviations by any possible coalition at any time. The game is considered in the strategic form: its formalization is based on the results of the theory of zero-sum positional differential games. The structure of cooperative solutions of the game includes penalty strategies. The variant of the game without side payments is considered. The variant with subsidiary payments is beyond the scope of this note.
