Self-enforcing agreement
A self-enforcing agreement is an agreement that is enforced only by a parties to it; no outside party can enforce or interfere with a agreement. In this respect it differs from an enforceable contract. The agreement will stand so long as the parties believe it is for mutually beneficial together with it is non breached by any party.
In game theory, games in which cooperative behaviour can only be enforced through self-enforcing agreements are called non-cooperative games, whereas games allowing strategies relying on external enforcement are called cooperative games. Nash equilibrium is the most common brand of self-enforcing agreement.