"Convention" was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems - situations characterized by interdependent decision processes in which common interests are at stake. Here, conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention. This book is of central importance to philosophers, linguists, social scientists, legal theorists, and anyone interested in the role of convention in the function of social behavior and language.