1. Introduction John Nash's (1951) theory of Nash equilibrium has been a central concept in game theories and especially for a wide range of studies, from economics to the social and environmental sciences. In addition to game theory, David (2012) mentioned that there are three unrealistic traits of the standard economic model of human behavior – “unlimited rationality, unlimited willpower and unlimited selfishness – which behavioral economics modifies”. However, considering the assumption of Nash equilibrium theory, there is an assumption that all players in the game are rational and understand the rules of the game. This means that they know their opponents' choices and what reaction they will choose with the goal of profit maximization (or their own goal objectively). Below there will be further discussion and the practicality of Nash equilibrium will be illustrated.2. Model and discussionThe Nash equilibrium is the set of outcomes without any of the players having incentives to modify their strategies (whether pure or mixed) with profit maximization (or their objective objective).(Martin,2009;Michael et al.,2013) Using the very famous example of the non-zero sum game in game theory, the prisoner's dilemma, is the simplest way to understand the basic means of Nash equilibrium. The police discovered two thefts and are now reporting. Once given a profit matrix of thefts (Fig. 1.) and the result of how many months they are in prison, since the theft is telling the truth (Cooperate) or lying (Flaw), the first profit will be that of player 1 and the next second will represent player 2. (James et al., 1993) Fig 1. The prisoner's dilemma - Rational cooperation in the infinitely repeated prisoner's dilemma...... middle of paper ...... 012) . Is behavioral economics doomed?. Cambridge: Open Book Publisher CIT Ltd. Available from: http://www.openbookpublishers.com/reader/77 [Accessed 13 November 2013]Martin J.Osborne. (2009). Nash equilibrium: theory. In: Introduction to game theory. New York: Oxford University Press. Inc. p13-53.Michael Maschler, Eilon Solan, Shmuel Zamir. (2013) Game Theory, trans. Ziv Hellman, USA, Cambridge University Press. Websites: Geoff Riley. (2012). Oligopoly and game theory. Available: http://tutor2u.net/economics/revision-notes/a2-micro-oligopoly-game-theory.html.[Accessed 14 November 2013]Newspaper articles: James Andreoni and John H. Miller. (1993). Rational cooperation in the infinitely repeated prisoner's dilemma: Experimental evidence. The economic newspaper. 103 (418), p570-585.John Nash. (1951). Non-cooperative games. The Annals of Mathematics. 52 (2), 286-295.