Res judicata is a legal term that refers to the prohibition or prevention of relitigating the same claims or causes of action already decided by the same two parties in an earlier lawsuit. That’s a clunky (legal) definition. Let’s try one better.
Basically, res judicta means that a plaintiff and defendant cannot go back to court to fight over claims or causes of action that have already been decided in court. Don’t waste the court’s time. “Res judicata” means “a thing decided or judged.” It is also known as claim preclusion. It is not issue preclusion. That’s another legal doctrine that prevents relitigating issues in the first lawsuit, even if the second lawsuit is based on different causes of action.
Another way to think about res judicata is that it gives conclusive effect (settles the matter permanently) to a former judgment.
Know that res judicata is an affirmative defense that’s waived unless affirmatively raised.
What are the requirements for res judicata to apply in California?
Three requirements must be met before the doctrine of res judicata applies. The first lawsuit:
- Reached a final judgment on the merits
- Involved the same claim or causes of action as the second lawsuit
- Involved the same parties as the second lawsuit
A few points on those requirements. You need a final judgment. Default judgments count as final judgments. A default judgment is res judicata to all claims or causes of action brought in the complaint. Ely v Gray (1990) 224 Cal.App.3d 1257,
Although res judicata applies to claims or causes of action that were involved or litigated in the first lawsuit, it also applies to claims or causes of action that could have been litigated. This is sometimes known as the primary right theory. It prevents splitting a legal action.
Finally, the “same parties” requirement also covers the parties’ agents.