Efficient computation of equilibria for extensive two-person games

The Nash equilibria of a two-person, non-zero-sum game are the solutions of a certain linear complementarity problem (LCP). In order to use this for solving a game in extensive form, the game must first be converted to a strategic description such as the normal form. The classical normal form, however, is often exponentially large in the size of the game tree. If the game has perfect recall, a linear-sized strategic description is the sequence form. For the resulting small LCP, we show that an equilibrium is found efficiently by Lemke's algorithm, a generalization of the Lemke-Howson method. Journal of Economic Literature Classification Number: C72. © 1996 Academic Press, Inc.