Study guide
7.5 Impossibility, Impracticability & Frustration of Purpose
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1 Introduction & FYLSE Examination Guide
1.1 FYLSE Exam Structure, Passing Standard & Administration 1.2 Study Method, Pacing & MBE-Style Technique
2 Contracts: Mutual Assent, Capacity & Contract Formation
2.1 The Offer & Objective Theory of Assent 2.2 Termination & Irrevocability of Offers 2.3 Acceptance & the Mailbox Rule 2.4 Mirror Image Rule & UCC 2-207 Battle of the Forms 2.5 Mistake in Contract Formation 2.6 Fraud, Duress, Undue Influence & Illegality 2.7 Capacity to Contract
3 Contracts: Consideration, Estoppel & Implied Obligations
3.1 Consideration & the Bargained-For Exchange 3.2 Past & Moral Consideration, Pre-Existing Duty & Modification 3.3 Promissory Estoppel & Detrimental Reliance 3.4 Implied-in-Fact Contracts & Quasi-Contract 3.5 Implied Covenant of Good Faith, Fair Dealing & Indefinite Terms
4 Contracts: Third-Party Beneficiaries, Assignment & Delegation
4.1 Third-Party Beneficiary Contracts 4.2 Assignment of Rights 4.3 Delegation of Duties
5 Contracts: Statute of Frauds, Parol Evidence & Interpretation
5.1 Statute of Frauds: Contracts Within the Statute 5.2 Satisfying the Statute: Writing, Signature & Exceptions 5.3 The Parol Evidence Rule 5.4 Contract Interpretation & Canons of Construction
6 Contracts: Performance, Conditions, UCC Warranties & Breach
6.1 Conditions: Express, Constructive & Excuse 6.2 Substantial Performance vs. Perfect Tender 6.3 Cure, Rejection, Revocation & Installment Contracts 6.4 UCC Article 2 Warranties & Risk of Loss 6.5 Anticipatory Repudiation & Insecurity
7 Contracts: Remedies, Discharge & Changed Circumstances
7.1 Expectation Damages & Their Limitations 7.2 Reliance, Restitution & Liquidated Damages 7.3 Specific Performance & Injunctive Relief 7.4 UCC Article 2 Buyer's and Seller's Remedies 7.5 Impossibility, Impracticability & Frustration of Purpose 7.6 Discharge by Agreement: Rescission, Novation & Accord and Satisfaction
8 Criminal Law: Principles of Criminal Liability & Mens Rea
8.1 Actus Reus, Voluntary Acts & Omissions 8.2 Criminal Causation & Intervening Causes 8.3 Common Law & Model Penal Code Mens Rea 8.4 Mistake of Fact, Mistake of Law & Concurrence
9 Criminal Law: Inchoate Offenses & Accomplice Liability
9.1 Criminal Attempt & Impossibility 9.2 Solicitation & the Merger Doctrine 9.3 Conspiracy & Merger Doctrine 9.4 Accomplice Liability: Actus Reus & Mens Rea 9.5 Scope of Accomplice Liability, Withdrawal & Parties to Crime
10 Criminal Law: Homicide & Crimes Against the Person
10.1 Common Law Murder & Malice Aforethought 10.2 Degrees of Murder, Premeditation & Deliberation 10.3 The Felony Murder Rule & Its Limitations 10.4 Voluntary & Involuntary Manslaughter 10.5 Non-Homicide Crimes Against the Person
11 Criminal Law: Property Crimes, Theft & Habitation
11.1 Common Law Larceny 11.2 Embezzlement & False Pretenses 11.3 Robbery & Extortion 11.4 Receiving Stolen Property 11.5 Burglary 11.6 Arson
12 Criminal Law: Defenses: Capacity, Justification & Excuse
12.1 Insanity: The Four Legal Tests 12.2 Intoxication, Diminished Capacity & Infancy 12.3 Self-Defense & Defense of Others 12.4 Defense of Property, Habitation & Law Enforcement Privileges 12.5 Duress & Necessity 12.6 Entrapment & Mistake as an Excuse
13 Torts: Intentional Torts to Persons & Property
13.1 Intent, Motive & Incapacity in Intentional Torts 13.2 Transferred Intent 13.3 Battery & Assault 13.4 False Imprisonment 13.5 Trespass to Land 13.6 Trespass to Chattels & Conversion
14 Torts: Privileges & Defenses to Intentional Torts
14.1 Consent: Express, Implied & Capacity 14.2 Exceeding & Vitiating Consent 14.3 Self-Defense & Defense of Others (Tort) 14.4 Defense of Property & Recapture of Chattels 14.5 Public & Private Necessity 14.6 The Shopkeeper's Privilege
15 Torts: Negligence — Duty of Care & Breach
15.1 Duty of Care & the Foreseeable Plaintiff 15.2 Affirmative Duties to Act & Special Relationships 15.3 Standard of Care: The Reasonable Person & Children 15.4 Professional Negligence, Informed Consent & Negligence Per Se 15.5 Land Possessor Liability & Premises Duties 15.6 Breach of Duty & Res Ipsa Loquitur
16 Torts: Causation, Defenses, Multiple Tortfeasors, Wrongful Death & Damages
16.1 Cause in Fact & Multiple Actors 16.2 Proximate Cause & Intervening Forces 16.3 Contributory, Comparative Negligence & Assumption of Risk 16.4 Joint and Several Liability, Contribution & Indemnity 16.5 Vicarious Liability & Non-Delegable Duties 16.6 Wrongful Death & Survival Actions 16.7 Statute of Limitations & Claim Accrual 16.8 Tort Damages: Compensatory, Nominal, Punitive & Mitigation
17 Torts: Strict Liability & Products Liability
17.1 Strict Liability for Animals 17.2 Abnormally Dangerous Activities & Scope of Risk 17.3 Strict Products Liability & Defect Categories 17.4 Products Liability Under Negligence, Warranty & Misrepresentation 17.5 Defenses to Products Liability
18 Torts: Emotional Distress, Defamation, Privacy & Economic Torts
18.1 Intentional Infliction of Emotional Distress 18.2 Negligent Infliction of Emotional Distress 18.3 Common Law Defamation: Elements, Libel & Slander 18.4 Constitutional Limits, Privileges & Defenses to Defamation 18.5 Invasion of Privacy 18.6 Nuisance & Economic Torts
7.5 Impossibility, Impracticability & Frustration of Purpose
Key Takeaways Explain This Topic AI
Objective impossibility excuses performance where no one could perform, as with destruction of the contract's subject matter or death of a person essential to performance.
Impracticability excuses performance made extremely and unreasonably difficult by an event whose non-occurrence was a basic assumption, but a mere increase in cost is not enough.
Frustration of purpose excuses a party whose principal purpose is substantially frustrated even though performance remains entirely possible.
All three require that the event was unforeseen and that the party seeking excuse did not bear the risk, either by agreement or by fault.
Temporary impossibility suspends rather than discharges the duty, unless performance afterwards would be materially more burdensome.
Last updated: September 2026
Impossibility, Impracticability & Frustration of Purpose
The Problem of Supervening Events: At early common law, contractual promises were strictly enforced as absolute undertakings ( Paradine v. Jane (1647)); if a party promised to perform, unexpected hardships, fires, or plagues did not excuse breach. Modern contract law recognizes that contracts are founded upon unstated baseline assumptions. When unforeseen external events radically alter the foundation of the bargain without the fault of either party, equity and the Restatement (Second) of Contracts provide three related doctrines of excuse: impossibility , impracticability , and frustration of purpose .
I. The Three Changed Circumstances Doctrines of Excuse
To successfully assert an excuse based on changed circumstances, the claiming party must establish that: (1) a supervening event occurred after contract formation; (2) the non-occurrence of that event was a basic assumption on which the contract was made; (3) the event occurred without the fault of the claiming party; and (4) the claiming party did not assume the risk of the event by agreement or custom. ┌──────────────────────────────────────┐
- │ Changed Circumstances Doctrines │
- └──────────────────┬───────────────────┘
- │
- ┌──────────────────────────────────┼──────────────────────────────────┐
- ▼ ▼ ▼
- [Objective Impossibility] [Commercial Impracticability] [Frustration of Purpose]
- Restatement § 261 - UCC § 2-615 / Restatement § 261 - Restatement § 265
- "The thing cannot be done" - Extreme & unreasonable difficulty - "Performance is possible,
- Death of essential person or catastrophic expense but the point is gone"
- Destruction of subject matter - Shortage from war / embargo - Krell v. Henry coronation
- Supervening illegality - Market price shifts NEVER excuse - Value virtually destroyed
- 1. Objective Impossibility (Restatement (Second) of Contracts § 261)
The Golden Rule: The standard is objective ( "the thing cannot be done by anyone" ), not subjective ( "I personally cannot do it due to financial inability or illness" ).
The Three Recognized Common Law Categories:
Death or Incapacity of an Essential Person: In a contract for personal services where the identity, skill, or artistic talent of a specific individual is indispensable to the performance (e.g., a portrait painter, an elite surgeon, a named celebrity singer), the death or disabling illness of that person discharges the contract.
Destruction or Deterioration of Subject Matter ( Taylor v. Caldwell ): Where the continued existence of a specific thing or means of performance is necessary for performance, its accidental destruction discharges the contract. In Taylor v. Caldwell (3 B. & S. 826 (1863)), the accidental burning of the Surrey Music Hall discharged the hall owner from liability to a concert promoter.
Supervening Illegality or Governmental Prohibition: If a domestic statute, executive decree, or judicial injunction enacts a legal ban that makes performance illegal after formation, the duty of performance is discharged.
Temporary Impossibility: If the impossibility is temporary (e.g., a temporary embargo or military call-up), the duty of performance is merely suspended ; it is discharged only if performance after the cessation of the impossibility would be substantially more burdensome.
2. Commercial Impracticability (UCC § 2-615 & Restatement § 261)
Modern commercial law recognizes that literal physical impossibility is too harsh a standard. Under UCC § 2-615 and Restatement (Second) of Contracts § 261 , performance is excused by commercial impracticability if performance can only be accomplished with extreme, unreasonable difficulty, expense, or injury .
Caution
The Price Spike Trap on the FYLSE: Mere market price increases, cost fluctuations, or normal inflationary pressures NEVER excuse performance under commercial impracticability.
Commercial sellers are in the business of assuming market risk. A 50%, 100%, or even 200% spike in the price of raw materials (such as lumber, oil, or steel) is treated as a foreseeable risk allocated to the seller. Impracticability requires a catastrophic, unforeseen event (e.g., a war closing an international canal, a crop plague destroying an entire region's harvest, an unannounced trade embargo cut-off) that destroys the contemplated supply source.
UCC § 2-615(b) Proration Requirement: If an unforeseen contingency affects only a part of a seller's capacity to deliver, the seller cannot simply fulfill orders for favored customers and repudiate the rest . The seller must allocate production and deliveries among customers in a manner that is fair and reasonable , and seasonably notify buyers of the estimated quota.
3. Frustration of Purpose ( Krell v. Henry & Restatement § 265)
Under the doctrine of frustration of purpose, physical and legal performance remains completely possible , but an unexpected supervening event has virtually destroyed the entire value or mutually understood point of the contract for one of the parties.
Origin: Krell v. Henry ([1903] 2 K.B. 740). The defendant rented an apartment flat for two days solely to view the coronation procession of King Edward VII. The king fell critically ill, and the coronation was canceled. The flat was physically available, and the defendant was financially able to pay. The court held that the defendant was discharged because the viewing of the procession was the mutually understood foundation and sole purpose of the contract.
Elements under Restatement § 265:
- The supervening event virtually completely destroys the principal purpose of the contract;
- The non-occurrence of the event was a basic assumption of both parties at formation; and
The frustration is near total (a mere reduction in profitability is insufficient).