In two experiments, decision makers chose between risky and ambiguous gambles under conditions of both single (unrepeated) and multiply repeated choices. The gambles were presented either as modified Ellsberg urn choices or as marketing strategy decisions. In both experiments, decision makers...

The problem of ambiguity in games is discussed, and a class of ambiguous games is identified. 195 participants played strategic-form games of various sizes with unidentified co-players. In each case, they first chose between a known-risk game involving a co-player indifferent between strategies...