Chapter 19 Game and decision theoretic models in ethics This chapter focuses on the game and decision theoretic models in ethics. The theory of rational behavior in a social setting can be divided into game theory and ethics. Game theory deals with two or more individuals often having very different interests who try to maximize their own (selfish or unselfish) interests in a rational manner against all the other individuals who likewise try to maximize their own (selfish or unselfish) interests in a rational manner. Ethics deals with two or more individuals often having very different personal interests yet trying to promote the common interests of their society in a rational manner. The chapter discusses the axioms of Bayesian decision theory an equi probability model for moral value judgments axioms for rational choice among alternative social policies use of von Neumann Morgenstern utilities in ethics rule utilitarianism act utilitarianism Rawls and Brocks nonutilitarian theories of justice and Brocks theory of social justice based on the Nash solution and on the Shapley value.