The doctrine of res judicata describes a set of rules that determine the preclusive effects of a final judgment on the merits. The California doctrine has two familiar components: a primary aspect, “res judicata” or claim preclusion; and a secondary aspect, “collateral estoppel” or issue preclusion. Under the claim preclusion aspect, a prior judgment bars the parties (or those in privity with them) from relitigating the “same cause of action” in a subsequent proceeding. Under the issue preclusion aspect, although a second suit between the same parties on a different cause of action is not precluded by a prior judgment, the first judgment operates as a conclusive adjudication as to such issues in the second action as were “actually litigated and determined” in the prior proceeding.
Walter W. Heiser,
California’s Unpredictable Res Judicata (Claim Preclusion) Doctrine,
San Diego L. Rev.
Available at: https://digital.sandiego.edu/sdlr/vol35/iss2/5