Hume is rightly credited with giving a brilliant, and perhaps the best, account of justice as convention. Hume's importance as a forerunner of modern economics has also long been recognized. However, most of Hume's readers have not fully appreciated how closely Hume's analysis of convention foreshadows a particular branch of economic theory, namely, game theory. Starting with the work of Barry (1965), Runciman and Sen (1965) and Lewis (1969), there has been a flowering of literature on the informal game-theoretic insights to be found in classics of political philosophy such as Hobbes (1651), Locke (1690), Hume (1740) and Rousseau (1755). A number of authors in this tradition, including Lewis (1969), Gauthier (1979), Mackie (1980), and Postema (1995), have identified passages in Hume which they interpret as giving informal examples of specific games. Yet, unlike his predecessors, Hobbes and Locke, Hume does much more than present examples which have a game-theoretic structure. In his account of convention, Hume gives general conditions which characterize the resolution of social interaction problems, and in the examples he uses to illustrate this account, Hume outlines several different methods by which agents can arrive at such a resolution. Hume's general account of convention and his explanations of the origins of particular conventions together constitute a theory of strategic interaction, which is precisely what game theory aspires to be.