 Arguably the most systematic use of game theory in moral and political philosophy has been in contractarian approaches to justifying moral or political orders. Philosophers have typically characterized the social contract as a set of rules for regulating the interactions of members of a community. By providing a formal model of interactive decision-making, game theory is clearly relevant to the analysis of such contracts. What has been particularly distinctive of game theoretic analysis of the social contract, though, is an emphasis on bargaining problems. As we will discuss below, the Nash bargaining problem provides a simple, yet flexible and conceptually powerful framework for identifying which of the rules that might comprise a contract can be said to be mutually beneficial (or acceptable) to each member of a community. In the main text of the two subsections that follow we try to present a relatively non-technical overview of this framework. Where formal characterizations of concepts are important, or where discussion of technical issues is likely to be illuminating for some readers, we’ve included such discussion in notes that appear at the end of the respective subsections. For a more thorough analysis of contractarian approaches to justifying moral and political orders, including further discussion of some of these technical issues, see the entry on  contemporary approaches to the social contract.