402 U.S. 313 (1971)
Blonder-Tongue Laboratories, Inc. v.
Does the doctrine of non-mutual defensive collateral estoppel preclude a plaintiff from relitigating a patent issue that was previously adjudicated to be invalid against another defendant?
A party who has had a full and fair opportunity to litigate a claim or issue in a prior proceeding cannot relitigate the same claim or issue in a subsequent action against a different party using defensive collateral estoppel, provided fairness considerations to all parties are maintained.
The U.S. Supreme Court held that defensive collateral estoppel can be applied even without mutuality of parties, provided the party against whom the estoppel is invoked had a 'full and fair opportunity' to litigate the issue in the prior action.
This case is significant for law students as it represents a critical shift from traditional doctrines of mutual estoppel to a more efficient and pragmatic approach in dealing with repetitive litigation. It demonstrates how the Court can adapt established legal doctrines to enhance the administration of justice, particularly in reducing duplicative litigation and conserving judicial resources. Law students must understand this case to appreciate the current application of collateral estoppel and its impact on both civil procedure and patent law.