Trees and Extensive Forms

Carlos Alós-Ferrer, University of Konstanz
Klaus Ritzberger, Institute for Advanced Studies, Vienna

Abstract

This paper addresses the question of what it takes to obtain a well-defined extensive form game. Without relying on simplifying finiteness or discreteness assumptions, we characterize the class of game trees for which (a) extensive forms can be defined and (b) all pure strategy combinations induce unique outcomes. The generality of the set-up covers "exotic'' cases, like stochastic games or decision problems in continuous time (differential games). We find that the latter class fulfills the first, but not the second requirement.