Which doctrine bars parties to a lawsuit on which final judgment has been rendered from bringing a second lawsuit on the same claim or related transactions?

• A. Collateral estoppel
• B. Res judicata
• C. Judgment non obstante
• D. Status quo ruling

Answer: (B)

Res judicata, or claim preclusion, bars a party from relitigating a claim after there is a final judgment on its merits. It applies when there has been a prior, final judgment, the same parties or their privies are involved, and the second action involves the same claim or a claim arising from the same transaction or set of facts. This ensures finality and prevents piecemeal lawsuits based on the same underlying dispute. For example, if a lawsuit seeks damages from a car crash and ends with a final judgment on that claim, a subsequent suit for damages arising from the same crash (or the same transaction) is barred.

Collateral estoppel, by contrast, prevents relitigation of specific issues that were actually litigated and necessarily decided in a prior case, not the entire claim. Judgment notwithstanding the verdict is a post-trial remedy to overturn a verdict, not a doctrine that blocks a new suit. A “status quo ruling” is not a standard, recognized doctrine in this context.