Game theory is a model that emerged in the field of mathematics and has become a popular subject of today, finding a place in many disciplines from economics to computer science. The model, which has competition, conflict, cooperation and decision-making elements, is called game theory, depending on the interaction of more than one decision-maker, and individual decisions are not included in the scope of game theory. In this paper, explanations about game theory are given in general and interlibrary competition, cooperation and decision-making processes of library administrations are evaluated in terms of game theory. [ABSTRACT FROM AUTHOR]