Non-cooperative game theory
In game theory, the non-cooperative game is a game with competition between individual players, as opposed to cooperative games, in addition to in which alliances can only operate if self-enforcing e.g. through credible threats. However, 'cooperative' in addition to 'non-cooperative' are only technical terms to describe the concepts used to framework a game, so this is the possible to use cooperative game notion to improvement example competition and using non-cooperative game theory to model cooperation.
The key distinguishing feature is the absence of external guidance to creation rules enforcing cooperative behavior. In the absence of external authority such as contract law, players cannot combine into coalitions and must compete independently.
Negative-sum game and Zero-sum game are both set of non-cooperative games.