⚡ 10-Second Rule
You get one lawsuit for each event, so bring every claim from it, because you can't come back for seconds.
🧒 ELI-10 Scene
Dev's brother crashed his bike into Dev's stuff and wrecked both his kite and his skateboard. At dinner, Dev complains to Mom only about the kite. Mom hears both sides, rules, and closes the case. The next night Dev tries again: "He also broke my skateboard!" Mom shakes her head. One crash, one complaint session. Dev knew about the skateboard yesterday. He had his chance to bring everything from that crash, and the kitchen court is closed.
⚖️ Actual Rule
Claim preclusion (res judicata) bars a second action when three elements are met: (1) a valid final judgment on the merits in the first action; (2) the same parties, or those in privity with them, in both actions; and (3) the same claim. Under the federal and majority transactional approach, paraphrasing Restatement (Second) of Judgments § 24, a "claim" includes all rights to relief arising from the same transaction or series of connected transactions, judged by whether the facts are related in time, space, origin, and motivation. The bar covers claims that were raised and claims that could have been raised. On what counts as "on the merits," FRCP 41(b) provides: "Unless the dismissal order states otherwise, a dismissal under this subdivision (b) and any dismissal not under this rule—except one for lack of jurisdiction, improper venue, or failure to join a party under Rule 19—operates as an adjudication on the merits." So judgments after trial, summary judgments, default judgments, and dismissals for failure to state a claim generally preclude, while dismissals for lack of jurisdiction, improper venue, or failure to join a required party do not.
ELI-10 translation: after one real, finished decision between the same people, every claim from that same event is used up — even the ones never mentioned.
[NJ-VARIANT: flagged for future Eli Explains NJ Law module]
🔍 Ask These Questions
- Is there a final judgment in case one? (Did the first fight actually end, not just pause?)
- Was it on the merits? (Did someone lose for real — not just knock on the wrong courthouse door?)
- Are the parties in case two the same people or their stand-ins? (Same fighters, or someone legally standing in their shoes, like a successor?)
- Does case two arise from the same transaction as case one? (Same crash, same contract, same event — even with a new legal label?)
- Could the new claim have been brought the first time? (If Dev knew about the skateboard, he had to mention it then.)
- If any element fails, switch lenses and check issue preclusion instead. (A different, narrower door might still close part of the case.)
⚠️ Bar Trap
Exam language: Examiners have a plaintiff sue on one theory — say, property damage in negligence — then bring a second suit from the same occurrence on a different theory or for a different injury, and bait you into calling it a new claim. A dressed-up variant offers a prior dismissal for lack of subject-matter jurisdiction as the "final judgment on the merits," which it never is.
ELI-10: A new label or a new bruise from the same crash is still the same claim. And losing because the court couldn't hear you isn't really losing — you can try again in the right court.
🧪 Question
A cyclist sued a delivery company in federal court, properly invoking diversity jurisdiction, alleging that the company's van negligently struck her at an intersection and seeking damages for her destroyed racing bicycle. After a bench trial, the court entered final judgment awarding the cyclist $9,000. Eight months later, the cyclist sued the same delivery company in the same court, seeking damages for a shoulder injury she suffered in the same collision, supported by medical records that existed at the time of the first trial. The company moved to dismiss on preclusion grounds.
How should the court rule?
(A) Grant the motion, because the shoulder claim arises from the same transaction already reduced to a final judgment on the merits between the same parties. (B) Deny the motion, because personal injury and property damage are distinct causes of action seeking different remedies. (C) Deny the motion, because the shoulder injury was never actually litigated or decided in the first action. (D) Grant the motion, because issue preclusion bars the cyclist from relitigating the collision.
Answer: (A). All three elements are satisfied: a final judgment on the merits, identical parties, and a second claim arising from the same transaction — the single collision. The shoulder claim could have been brought in the first suit, so claim preclusion extinguishes it.
💡 Why the Wrong Answers Are Wrong
- (B) applies the abandoned narrow same-evidence view; the transactional test merges all injuries from one occurrence into one claim.
- (C) states the test for issue preclusion; claim preclusion bars even claims never litigated, so long as they could have been raised.
- (D) reaches the right result under the wrong doctrine; issue preclusion targets decided issues, and the winning ground here is claim preclusion.
- ELI-10: The misconception is thinking each injury or legal theory buys a new lawsuit. One event is one ticket, and the ticket gets punched once.
