  We introduce a solution concept for extensive-form games of incomplete
information in which players need not assign likelihoods to what they do not
know about the game. This is embedded in a model in which players can hold
multiple priors. Players make choices by looking for compromises that yield a
good performance under each of their updated priors. Our solution concept is
called perfect compromise equilibrium. It generalizes perfect Bayesian
equilibrium. We show how it deals with ambiguity in Cournot and Bertrand
markets, public good provision, Spence's job market signaling, bilateral trade
with common value, and forecasting.
