What does res judicata mean?

• A. A court's authority to retry a case on appeal
• B. The principle that a matter cannot be relitigated once finally adjudicated
• C. A rule allowing new evidence to be admitted on appeal
• D. A method for enforcing judgments through collection actions

Answer: (B)

Res judicata means a matter cannot be relitigated after a final judgment on the merits has been entered. Once a court has resolved a claim with a final decision, the same parties generally cannot bring another lawsuit based on that same claim or cause of action. This rule creates finality and judicial economy, preventing endless disputes over the same issue. It’s about closing the door on a claim after it has been finally decided.

Related ideas include collateral estoppel, which bars relitigation of a specific issue that was actually litigated and decided in a prior case, even if the new case involves a different claim. The other options don’t fit because one describes retrying on appeal, another refers to admitting new evidence on appeal, and the last concerns post-judgment collection actions rather than blocking relitigation of a settled claim.