The game theory represents a mathematical theory and methodology which is used for solving conflicting and partly conflicting situations in which individuals have conflicting interests. Considering situations in which two or more subjects make decisions in the conditions of interest conflict has been named the theory of game because the typical examples of such situations represent various types of social games, such as the chess, card games, sport games, etc. Even tough most of the notions used in the game theory resemble the terminology of social games, the game theory has much broader use and it is used for modeling conflicting situations in the mathematics, military strategy, politics, economics, etc. The concepts of game theory have been increasingly used in the law. The purpose of this paper is to present the game theory and show how this mathematical theory can be used for the purpose of legal decision making. The particular emphasis is placed on the prisoner's dilemma as one of the most popular and most used models of game theory and its application in selected branches of law. PUBLICATION ABSTRACT