What does res judicata mean?

• A. It means the thing is decided—refers to that which has been previously acted on or decided by the courts. Bars subsequent actions involving the same claim, demand, or cause of action
• B. A doctrine allowing new evidence after a verdict
• C. A rule requiring jurors to base verdicts on evidence
• D. A requirement that a case be heard in the state where it arose

Answer: (A)

Res judicata means a matter has been finally decided by a court and cannot be pursued again. Once a judgment on the merits is final, the same parties generally cannot bring another lawsuit based on the same claim or cause of action—the judgment bars future actions. This provides finality and prevents duplicative litigation. It usually applies when the prior case resolved the claim between the same parties (or those in privity). A related idea, collateral estoppel, bars relitigation of specific issues already decided, but res judicata focuses on the entire claim itself. The other options describe different concepts, such as allowing new evidence after a verdict, jurors basing verdicts on evidence, or venue requirements.