Restitution & Unjust Enrichment
Remedies · Lesson 03
Restitution & Unjust Enrichment
這一課問的是：D 是否因 P 之利益而不當得利？應給予何種返還救濟？
ActorActObjectStandardConsequence
Visual Scene · the picture in your head
Issue. Has D been unjustly enriched at P's expense — and what restitutionary remedy applies?
這一課問的是：D 是否因 P 之利益而不當得利？應給予何種返還救濟？
Core Terminology · 7 must-know
Tap a card to flip and reveal the meaning.
restitution
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Remedy aimed at preventing unjust enrichment.
返還。
unjust enrichment
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Defendant retains benefit at plaintiff's expense in circumstances making retention unjust.
不當得利。
quantum meruit
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Restitution for services rendered.
當得。
quasi-contract
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Implied-in-law obligation to prevent unjust enrichment.
準合約。
constructive trust
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Equitable remedy: imposes trust on wrongfully held property.
推定信託。
equitable lien
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Charge on property to secure restitutionary claim.
衡平留置。
disgorgement
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D returns wrongfully obtained gain.
返還所得。
Issue · what this lesson is really about
Has D been unjustly enriched at P's expense — and what restitutionary remedy applies?
這一課問的是：D 是否因 P 之利益而不當得利？應給予何種返還救濟？
Trigger words & phrases that should flag this issue:
benefitenrichmentunjustdisgorgementconstructive trust
Expression Bank · how lawyers actually say it
Six function → sentence patterns. Use these in essay applications.
| Function | English sentence | 中文 |
|---|---|---|
| State elements | Unjust enrichment requires (1) D's benefit at P's expense, (2) circumstances making retention unjust. | 不當得利二要件。 |
| Apply quantum meruit | Restitution for services rendered may be the fair value. | 勞務之返還以合理價值計。 |
| Apply constructive trust | Property wrongfully held may be held in constructive trust for P. | 可推定信託於 P。 |
| Apply equitable lien | P may obtain a lien on property to secure the restitutionary claim. | 可在財產上設衡平留置。 |
Rule Sentence · the workhorse
Restitution prevents unjust enrichment: a defendant who has been unjustly enriched at the plaintiff's expense must restore the benefit; available restitutionary remedies include quasi-contract (quantum meruit), constructive trust, equitable lien, and disgorgement of wrongful gain.
Sentence Anatomy · 5 roles, 5 colors
Every rule sentence breaks into five visual roles.
Actor 行為人plaintiff原告
Act 行為seeking restitution請求返還
Object 對象unjust benefit不當利得
Standard 法律標準unjust enrichment elements + remedy choice不當得利要件 + 救濟選擇
Consequence 後果benefit restored to P利得歸還 P
Casebook Snapshot · a real American case
Pyeatte v. Pyeatte
Holding. Where one spouse provides extraordinary financial support to put the other through professional school in reliance on a promise to reciprocate, and the supported spouse fails to keep the promise, restitution may be awarded to prevent unjust enrichment.
Why it matters. Pyeatte illustrates restitution outside contract: equity prevents unjust retention of benefits.
Pyeatte：合約失敗後仍可不當得利返還。
Common Mistakes · what trips students
✗ restitution 等於 damages。
✓ Restitution is gain-based; damages are loss-based.
返還以利得算；賠償以損失算。
✗ constructive trust 須事前約定。
✓ Constructive trust is imposed by court regardless of agreement.
推定信託由法院強加。
Mini IRAC · build the Application
Issue. May P, who rendered legal services to D under a contract void due to D's fraud, recover the fair value of services?
Rule. Restitution under quantum meruit allows recovery of the fair value of services rendered where retention of the benefit would unjustly enrich the defendant.
Application (model). P performed legal services for D under a contract that turned out to be voidable due to D's fraud. Because quantum meruit permits restitution of the fair value of services where retention of the benefit would unjustly enrich the defendant, the fact that D received P's professional legal services and the contract is unenforceable due to D's own fraud means D would be unjustly enriched if no restitution were available.
Pick the right element for each blank:
g1.
g2.
g3.
Conclusion. Therefore, P may recover the reasonable value of services rendered.
MBE Check · multiple choice
D, a fiduciary, uses $100,000 of P's funds to buy stock that increases in value to $300,000. P discovers the misconduct. What restitutionary remedy is best?
Mini Essay · write the Application paragraph
Facts. D embezzled $500,000 from P over five years. D used the money to buy a beach house now worth $2 million.
Call. What restitutionary remedies are available to P?
Practice Drill · tap to build the rule
Drop the chips here in correct order:
Tap chips to add → tap chips in the target to remove: