Collateral Estoppel

Known in modern terminology as issue preclusion, is a common law Estoppel doctrine that prevents a person from relitigating an issue. One summary is that "once a court has decided an issue of fact or law necessary to its judgment, that Decision ... preclude[s] relitigation of the issue in a suit on a different cause of Action involving a party to the first case." The rationale behind issue preclusion is the prevention of legal harassment and the prevention of abuse of judicial resources.