We show that one can approximate an infinite action game by a finite action
game in the sense that every behavior strategy combination of the finite a
ction game can be mimicked by a behavior strategy combination of the infini
te action game so that the resulting payoffs from the behavior strategies c
annot differ by more than epsilon. Also for every behavior strategy of a pl
ayer i on a subgame of the infinite action game one can find a behavior str
ategy of player i of the finite action game which will give expected payoff
s that are close to each other on the particular subgame. We use these resu
lts to construct E-perfect equilibria of infinite action games. (C) 1999 El
sevier Science S.A. All rights reserved.