A mathematical formulation makes it easy to define concepts precisely, to verify the consistency of ideas, and to explore the implications of assumptions. The use of mathematical models creates independent mathematical interest. From our point of view the mathematical results are interesting only if they are confirmed by intuition. Games and Solutions A game is a description of strategic interaction that includes the constraints on the actions that the players can take and the players' interests, but does not specify the actions that the players do take. A solution is a systematic description of the outcomes that may emerge in a family of games.
Game theory suggests reasonable solutions for classes of games and examines their properties.
We now explain some of the dimensions on which this division is based. In all game theoretic models the basic entity is a player . A player may be interpreted as an individual or as a group of individuals making a decision. In Part I we discuss the concept of a strategic game and in Parts II and III the concept of an extensive game. In the models in Part II the participants are fully informed about each others' moves, while in the models in Part III they may be imperfectly informed.