MUTUALITY DOCTRINE

mutuality doctrine. The collateral-estoppel requirement that, to bar a party from relitigating an issue determined against that party in an earlier action, both parties must have been in privity with one another in the earlier proceeding. — Also termed mutuality of parties. [Cases: Judgment 666, 678. C.J.S. Judgments §§ 830, 833, 835, 861, 912.]