4.1 The prisoner’s dilemma
The prisoner’s Dilemma game was first proposed by Merill Flood (1951). In this game two suspects are captured by the police. The police suspect that they are in charge of a crime, but do not have adequate evidence to prove it in court. For shriving from criminals, police put them in separate cells without any communication to each other. If neither prisoner confesses, both will be convicted of about one year. If both confess to their crime then both will be sentenced to 5 years. If however, one prisoner confesses to his crime, while the other does not, then the prisoner who confessed will be forgiven while the prisoner who did not confess will be convicted to 10 years. In this stage the question which exists in the criminals’ mild is that which decision can be the best for each of them against the opponent’s decision. For answering to this question it is better to use game theory approach and Nash equilibrium solution. For implementing this game in the framework of game theory, firstly, the game should be written in matrix form. The value in each cell shows the time spent in prison.