Are Agreements to Cooperate Enforceable? 

In many of the games we will  see  interests  of the  player are a mixture of conflict and common interest. If all the participants get together and reach an agreement about what everyone should do to, balancing their mutual interest in  maximising  their total benefit and their conflicts in maximising their payoffs. But  this agreement to cooperate can succeed if all the players act immediately and in the presence of  the whole group but agreements with such immediate implementations are rare. Often participants disperse after the agreement  is  reached and then  they take  actions in private.  In many cases these individual actions are neither observable nor  enforceable by external forces. Game theory uses special terminology to capture the distinction between situations in which agreements are enforceable and in which they are not.

Games in which joint-action agreements are enforceable are called cooperative games and  the games in which such enforcement is not possible and  individual must be allowed to act in their own interest, are called non- cooperative games.