Making use of and following substantive rationality is a costly and not always feasible option. In games, this option … play an underlying game in which the alternatives are to follow either substantive rationality or a different rule, here … that of reasonableness, in playing the overt game. A strategy is reasonable if coupled with its best response it results in …

Aumann (1995) showed that for games with perfect information common knowledge of substantive rationality implies … backward induction. Substantive rationality is defined in epistemic terms, that is, in terms of knowledge. We show that when … substantive rationality is defined in doxastic terms, that is, in terms of belief, then common belief of substantive rationality …

characterizes common certainty of rationality in the universal type space. …

players (i) are rational,(ii) have strong belief in both opponents' rationality and opponents' capacity to observe others …' choices, and (iii) have common belief in both opponents' future rationality and op-ponents' future capacity to observe others …

In an epistemic framework due to Aumann we characterize the condition on the rationality of the players that is both …