collateral estoppel

Collateral estoppel, also known as issue preclusion, is a legal doctrine that prevents parties from relitigating an issue of fact in a second lawsuit if that issue was already decided in a prior case. This applies even if the second lawsuit is based on a different claim.1

For collateral estoppel to apply, several conditions must be met:
* The issue in the second lawsuit must be the same as the issue in the first lawsuit.1
* The issue must have been actually litigated and necessarily determined in the first suit.1
* The party against whom collateral estoppel is asserted must have had a full and fair opportunity to litigate the issue in the prior case.1

This doctrine aims to promote judicial efficiency and prevent inconsistent judgments by avoiding repetitive litigation. While traditionally limited to cases involving the same parties, many modern legal systems allow for its application even when different parties are involved, provided the issue and opportunity to litigate are the same.1