UBE Claim and Issue Preclusion
Last updated: May 2, 2026
Claim and Issue Preclusion questions are one of the highest-leverage areas to study for the UBE. This guide breaks down the rule, the elements you need to recognize, the named traps that catch most students, and a memory aid that scales to test day. Read it once, then practice the same sub-topic adaptively in the app.
The rule
Claim preclusion bars a party from relitigating a claim that was, or could have been, raised in a prior action when (1) the prior action ended in a valid final judgment on the merits, (2) the parties (or their privies) are the same in both actions, and (3) the second action involves the same claim — defined under the majority/Restatement (Second) of Judgments §24 'transactional' test as any claim arising from the same transaction or series of connected transactions. Issue preclusion bars relitigation of a specific issue of fact or law when (1) the issue was actually litigated and determined in the prior action, (2) the determination was essential to a valid final judgment, and (3) the party against whom preclusion is asserted had a full and fair opportunity to litigate. Federal courts give a state-court judgment the same preclusive effect that the rendering state would give it (28 U.S.C. §1738); federal judgments in federal-question cases follow federal common law of preclusion.
Elements breakdown
Claim Preclusion (Res Judicata)
A valid final judgment on the merits bars the same parties from relitigating any claim arising from the same transaction or occurrence, including claims that could have been but were not raised.
- Valid final judgment in prior action
- Judgment on the merits
- Same parties or those in privity
- Same claim under transactional test
Common examples:
- Plaintiff sues for property damage from a car accident, then sues for personal injuries from the same accident — barred
- Plaintiff loses contract suit, then sues on quasi-contract theory from same deal — barred
On the Merits Requirement
A judgment is on the merits if it adjudicates the substantive rights of the parties; certain dismissals are deemed on the merits by rule.
- Adjudicates substantive rights, OR
- Dismissal with prejudice under Rule 41(b)
- Excludes dismissals for lack of jurisdiction, venue, or improper joinder
- Default judgments and consent judgments qualify
Privity
A nonparty is bound by a prior judgment only in narrow circumstances recognized in Taylor v. Sturgell.
- Successor in interest to a party
- Nonparty controlled the prior litigation
- Adequate representation in class action or fiduciary suit
- Express agreement to be bound
- Suing as proxy/agent for prior party
Compulsory Counterclaim Bar (Rule 13(a))
A defendant who fails to assert a counterclaim arising from the same transaction or occurrence as the plaintiff's claim cannot later sue on it.
- Claim existed at time defendant served pleading
- Arises from same transaction or occurrence as plaintiff's claim
- Did not require adding party over whom court lacked jurisdiction
- Was not already subject of another pending action
Issue Preclusion (Collateral Estoppel)
A specific factual or legal issue actually litigated and necessarily decided in a prior action cannot be relitigated by a party who had a full and fair opportunity to litigate it.
- Same issue in both actions
- Issue actually litigated in prior action
- Issue actually determined by prior court
- Determination essential to the judgment
- Party to be bound had full and fair opportunity
Mutuality and Nonmutual Issue Preclusion
Modern federal rule abandons strict mutuality; a stranger to the prior action may invoke issue preclusion against a party who litigated and lost the issue.
- Defensive nonmutual: new defendant uses prior loss against same plaintiff — generally permitted (Blonder-Tongue)
- Offensive nonmutual: new plaintiff uses prior loss against same defendant — permitted with discretion (Parklane Hosiery)
- Court weighs incentive to litigate, foreseeability, procedural opportunities, inconsistent prior judgments
- Federal government generally not subject to nonmutual offensive preclusion (Mendoza)
Full Faith and Credit / 28 U.S.C. §1738
A federal court must give a state-court judgment the same preclusive effect that the courts of the rendering state would give it.
- Identify rendering state's preclusion law
- Apply that state's claim and issue preclusion rules
- Federal-question exclusivity does not defeat preclusion of issues already decided
- Applies even if second forum could not have entertained the claim originally
Common patterns and traps
The Transactional-Test Trigger
The MBE loves to test whether a 'new' claim is really the same claim under the Restatement transactional test. A plaintiff who litigated one legal theory (breach of contract) cannot later sue on a different theory (fraud, unjust enrichment, negligent misrepresentation) arising from the same deal. Look for facts where the plaintiff splits causes of action arising from a single accident, transaction, or relationship.
An answer choice that says 'No, because the second suit alleges a different legal theory than the first' — that is the wrong-rule trap; theory does not matter, transaction does.
The 'Actually Litigated and Essential' Cut
Issue preclusion fails if the issue was not actually litigated (default judgments, consent judgments, stipulations) or if the determination was not essential to the judgment (alternative grounds, dicta). Watch for facts where a court ruled on multiple independent grounds — older rule preclusion attaches to each; the Restatement (Second) §27 view is that neither alternative ground is preclusive.
An answer choice asserting issue preclusion based on a default judgment, or on a finding the prior court did not need to reach to render judgment.
The Nonparty Privity Trap
Taylor v. Sturgell narrowed nonparty preclusion to six categories. Bar questions tempt you to bind a nonparty because they have a 'similar interest' or were a 'virtual representative' — that argument was rejected. Without successor status, control, agency, class membership, fiduciary representation, or express agreement, a stranger is not bound.
An answer choice binding a second plaintiff because she is a family member, employee, or shares the same interest as the first plaintiff — wrong absent a Taylor category.
The Offensive Nonmutual Estoppel Question
When a new plaintiff seeks to use a prior loss against a defendant who already litigated the issue, Parklane Hosiery permits it but commits the decision to the trial court's discretion. Disfavored when the plaintiff could have easily joined the prior action ('wait-and-see plaintiff'), when the defendant had little incentive to litigate vigorously, or when prior inconsistent judgments exist.
An answer choice categorically barring offensive use because of lack of mutuality — wrong under federal law since 1979; or one categorically permitting it without weighing Parklane factors.
The §1738 / Choice-of-Preclusion-Law Issue
When a federal court evaluates the preclusive effect of a state-court judgment (or vice versa), 28 U.S.C. §1738 requires applying the rendering court's preclusion law. This trips candidates who instinctively apply federal preclusion principles to a state judgment, or who think exclusive federal jurisdiction over the new claim defeats preclusion.
An answer choice that applies federal claim-preclusion rules to a New York state-court judgment without first asking what New York would do.
How it works
Walk through these in the right order. First, ask whether you are dealing with claim preclusion (whole claim, same parties, same transaction) or issue preclusion (one discrete fact/law question that was actually decided). Suppose Reyes sues Patel in federal court for breach of a supply contract and wins; Reyes cannot later sue Patel on a fraud theory arising from the same negotiations — claim preclusion bars it because the fraud claim arose from the same transaction and could have been joined. Now suppose Liu sues Reyes Manufacturing for negligence in a forklift accident and the jury finds Reyes was not negligent; if a second injured worker, Okonkwo, later sues Reyes for the same incident, Okonkwo (a nonparty) is not bound, but if Reyes later sues Liu over the accident, Liu can offensively use the prior negligence finding against Reyes (Parklane Hosiery factors permitting). The judgment must be valid, final, and on the merits — a 12(b)(6) dismissal with prejudice qualifies; a 12(b)(2) dismissal for lack of personal jurisdiction does not. And for federal courts looking at state judgments, run the analysis under the rendering state's law per §1738.
Worked examples
How should the court rule on Reyes's motion?
- A Deny the motion, because Liu's personal injuries were not actually litigated or essential to the prior judgment.
- B Deny the motion, because Liu could not have known the full extent of her injuries when she filed the first action.
- C Grant the motion, because both claims arise from the same transaction and Liu was required to assert all claims arising from the collision in the first action. ✓ Correct
- D Grant the motion, but only as to the negligence determination; Liu may still litigate damages.
Why C is correct: This is classic claim preclusion under the Restatement (Second) of Judgments §24 transactional test. A valid final judgment on the merits between the same parties bars a second action arising from the same transaction or occurrence — here, the single collision. Liu was required to bring all damages claims (property and personal injury) in the first action; splitting damages by category is impermissible. The majority rule does not excuse claim-splitting because injuries later worsened.
Why each wrong choice fails:
- A: This conflates claim preclusion with issue preclusion. Claim preclusion does not require that the personal-injury claim be 'actually litigated' — it bars claims that could have been raised arising from the same transaction. (The 'Actually Litigated and Essential' Cut)
- B: The majority rule rejects a subjective-knowledge exception to claim preclusion for damages from a known injury-causing event; Liu knew of the collision and was on notice to plead all damages or seek to amend. (The Transactional-Test Trigger)
- D: This invents a partial-preclusion doctrine that does not exist in this posture. Once claim preclusion bars the second action, the entire suit is dismissed; the court does not 'carry over' isolated findings while permitting damages litigation.
Should the court grant the neighbors' motion?
- A No, because the doctrine of mutuality bars nonparties from invoking issue preclusion.
- B No, because the neighbors were not parties to the prior action and are not in privity with Patel.
- C Yes, because the causation issue was actually litigated, essential to the prior judgment, and Okonkwo had a full and fair opportunity to litigate. ✓ Correct
- D Yes, because Okonkwo is bound by the prior judgment under the doctrine of virtual representation.
Why C is correct: This is offensive nonmutual issue preclusion under Parklane Hosiery v. Shore. The causation issue was actually litigated and necessarily decided in the prior action, Okonkwo had every incentive to litigate vigorously (a $200,000 judgment), the neighbors' later use was foreseeable, and there are no inconsistent prior judgments. The Parklane discretionary factors all favor preclusion, so the trial court may permit it.
Why each wrong choice fails:
- A: Federal courts abandoned strict mutuality after Blonder-Tongue (defensive) and Parklane Hosiery (offensive). Mutuality is no longer a categorical bar in federal court. (The Offensive Nonmutual Estoppel Question)
- B: Privity binds nonparties to a prior judgment; here, the nonparties are using preclusion offensively against a party who already litigated. The party being precluded (Okonkwo) was a party to the prior suit, which is what matters. (The Nonparty Privity Trap)
- D: Taylor v. Sturgell expressly rejected 'virtual representation' as a basis for binding nonparties. More fundamentally, Okonkwo is being bound because it was the actual party in the prior suit, not via any privity theory. (The Nonparty Privity Trap)
How should the federal court rule?
- A Deny the motion, because federal courts apply federal preclusion law and federal RICO claims warrant a federal forum.
- B Deny the motion, because preclusion across state lines requires identity of the forum state.
- C Grant the motion, because under 28 U.S.C. §1738 the federal court must give the New York judgment the preclusive effect New York would give it, and New York applies a transactional test. ✓ Correct
- D Grant the motion, but only if Garcia could have asserted the RICO claim in the New York court.
Why C is correct: Under 28 U.S.C. §1738 (Full Faith and Credit Statute), a federal court must give a state-court judgment the same preclusive effect the rendering state's courts would give it. New York follows a transactional analysis akin to the Restatement (Second). Because the RICO claim arises from the same lease and collection transactions adjudicated in New York, it is barred. Marrese and Migra confirm that even claims within concurrent or exclusive federal jurisdiction can be precluded if state law would so provide.
Why each wrong choice fails:
- A: This ignores §1738. Federal courts do not apply federal preclusion law to a state-court judgment; they borrow the rendering state's preclusion law. (The §1738 / Choice-of-Preclusion-Law Issue)
- B: Preclusion does not require forum identity; full faith and credit operates precisely to give judgments cross-jurisdictional effect. The forum of the second suit is irrelevant to whether preclusion attaches.
- D: While the could-have-been-raised principle is part of the analysis, the operative source is New York's transactional test under §1738, not a free-standing federal inquiry. Phrasing the rule as a federal 'could have raised' test misstates the choice-of-law step. (The §1738 / Choice-of-Preclusion-Law Issue)
Memory aid
Claim preclusion = 'SAME claim, SAME parties' (transactional). Issue preclusion = 'ALE-FF': Actually Litigated, Essential to judgment, Full and Fair opportunity. For nonmutual offensive estoppel, remember 'PARK': Prior incentive, Adequate procedures, Reliance unforeseeable?, Konsistency (no inconsistent judgments).
Key distinction
Claim preclusion bars the entire second lawsuit (or specified claims) because it could have been litigated the first time; issue preclusion only bars relitigation of specific issues actually decided. The bar examiner's favorite trap: a plaintiff who lost on one theory tries a different legal theory from the same facts — that is barred by claim preclusion (transactional test), even though the specific 'issue' was never litigated.
Summary
Claim preclusion blocks relitigation of any claim arising from the same transaction between the same parties after a valid final judgment on the merits; issue preclusion blocks relitigation of a specific issue actually litigated, essential to a prior judgment, against a party who had a full and fair opportunity to litigate.
Practice claim and issue preclusion adaptively
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Start your free 7-day trialFrequently asked questions
What is claim and issue preclusion on the UBE?
Claim preclusion bars a party from relitigating a claim that was, or could have been, raised in a prior action when (1) the prior action ended in a valid final judgment on the merits, (2) the parties (or their privies) are the same in both actions, and (3) the second action involves the same claim — defined under the majority/Restatement (Second) of Judgments §24 'transactional' test as any claim arising from the same transaction or series of connected transactions. Issue preclusion bars relitigation of a specific issue of fact or law when (1) the issue was actually litigated and determined in the prior action, (2) the determination was essential to a valid final judgment, and (3) the party against whom preclusion is asserted had a full and fair opportunity to litigate. Federal courts give a state-court judgment the same preclusive effect that the rendering state would give it (28 U.S.C. §1738); federal judgments in federal-question cases follow federal common law of preclusion.
How do I practice claim and issue preclusion questions?
The fastest way to improve on claim and issue preclusion is targeted, adaptive practice — working questions that focus on your specific weak spots within this sub-topic, getting immediate feedback, and revisiting items you missed on a spaced-repetition schedule. Neureto's adaptive engine does this automatically across the UBE; start a free 7-day trial to see your sub-topic mastery climb in real time.
What's the most important distinction to remember for claim and issue preclusion?
Claim preclusion bars the entire second lawsuit (or specified claims) because it could have been litigated the first time; issue preclusion only bars relitigation of specific issues actually decided. The bar examiner's favorite trap: a plaintiff who lost on one theory tries a different legal theory from the same facts — that is barred by claim preclusion (transactional test), even though the specific 'issue' was never litigated.
Is there a memory aid for claim and issue preclusion questions?
Claim preclusion = 'SAME claim, SAME parties' (transactional). Issue preclusion = 'ALE-FF': Actually Litigated, Essential to judgment, Full and Fair opportunity. For nonmutual offensive estoppel, remember 'PARK': Prior incentive, Adequate procedures, Reliance unforeseeable?, Konsistency (no inconsistent judgments).
What's a common trap on claim and issue preclusion questions?
Confusing claim preclusion's 'same claim' transactional test with issue preclusion's 'same issue' analysis
What's a common trap on claim and issue preclusion questions?
Forgetting the 'essential to the judgment' requirement for issue preclusion
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