Res Judicata (Claim Preclusion)
A valid final judgment on the merits bars re-litigation of all claims that were or could have been raised in the first suit between the same parties or their privies — merger (plaintiff won) and bar (plaintiff lost).
Elements / Test
All four elements must be satisfied:
- Same parties (or those in privity — successors in interest, those who controlled prior litigation)
- Same claim — determined by the transactional test: all claims arising out of the same transaction or series of closely related transactions; not the same legal theory
- Valid final judgment on the merits — dismissal with prejudice counts; default judgment counts; dismissal for lack of jurisdiction does NOT
- Court of competent jurisdiction
Effects:
- Merger: If plaintiff won, claim merges into judgment; cannot re-litigate for more relief
- Bar: If plaintiff lost, claim is barred from re-assertion
Exceptions and Edge Cases
- Not on the merits: Dismissal for lack of jurisdiction, improper venue, or failure to join an indispensable party does not preclude re-filing
- Compulsory counterclaims (Rule 13(a)): Failure to raise a compulsory counterclaim may bar it in later suit
- Splitting claims: Plaintiff may not split a single cause of action across multiple suits
- Privity: Complicated — traditional categories (employer/employee, principal/agent, predecessor/successor); due process limits on non-party preclusion (Taylor v. Sturgell — no “virtual representation”)
- Different sovereigns: Federal and state court judgments generally entitled to full faith and credit; but some state courts more generous with federal preclusion rules
Policy Rationale
Finality, judicial efficiency, consistency of results, repose for defendants. Avoids harassment through repetitive litigation.
Key Cases
| Case | Rule |
|---|---|
| Federated Dept. Stores v. Moitie (1981) | res judicata bars re-filing even if dismissal was wrong on the merits |
| Taylor v. Sturgell (2008) | Non-party preclusion requires established exception; no general virtual representation doctrine |
| Mathews v. New York Racing Ass’n | Transactional test for same claim |