This paper generalizes the concept of best response to coalitions of players and offers epistemic definitions of coalitional rationalizability in normal form games. The best response of a coalition is defined to be a correspondence from sets of conjectures to sets of strategies. From every best...

In conventional epistemic analysis of solution concepts in complete information games, complete information is implicitly interpreted to mean common certainty of (i) a mapping from action profiles to outcomes; (ii) players' (unconditional) preferences over outcomes; and (iii) players'...

We introduce a game in preference form, which consists of a game form and a preference structure, and define preference rationalizability that allows for each player's ex-post preferences over outcomes to depend on opponents' actions. We show that preference rationalizability is invariant to...

An action is robustly rationalizable if it is rationalizable for every type who has almost common certainty of payoffs. We illustrate by means of an example that an action may not be robustly rationalizable even if it is weakly dominant, and argue that robust rationalizability is a very...