3.2 Past & Moral Consideration, Pre-Existing Duty & Modification

California First-Year Law Students' Examination Baby Bar

Track your progress as you read

Finished sections get a check mark.

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

3.2 Past & Moral Consideration, Pre-Existing Duty & Modification

Key Takeaways Explain This Topic AI

Past consideration is no consideration, because a performance already rendered cannot have been bargained for by a later promise.

Moral obligation alone will not support a promise, though a minority of courts enforce a later promise to pay for a material benefit previously conferred.

Under the pre-existing duty rule, a promise to do what a party is already contractually bound to do is not consideration for a modification.

A common-law modification needs new consideration or an unforeseen-circumstances exception, but UCC section 2-209(1) enforces a good-faith modification of a sale of goods without any consideration.

An illusory promise that leaves performance wholly to the promisor's discretion supplies no consideration and cannot make a bargain enforceable.

Last updated: September 2026

Past & Moral Consideration, Pre-Existing Duty & Modification
Defective Consideration: Past Consideration & Moral Obligation
Past Consideration Is No Consideration

An act or forbearance that occurred prior to the promisor's promise cannot serve as consideration. Because the act was already completed, the subsequent promise could not have induced the performance, nor was the performance given in exchange for the promise.

Rule: Past consideration is a contradiction in terms. Consideration must be given contemporaneously or executively in exchange for the promise.

Exceptions to the Past Consideration Rule

Debts Barred by Statute of Limitations: A subsequent promise to pay a contractual debt barred by the applicable statute of limitations is legally enforceable without fresh consideration (Restatement (Second) § 82). Most jurisdictions require the promise to be in a signed writing or evidenced by partial payment.

Reaffirmation of Debts Discharged in Bankruptcy: A promise to pay a debt discharged in bankruptcy can be enforceable without consideration, provided federal statutory requirements (Bankruptcy Code § 524) regarding reaffirmation agreements are strictly observed.

Moral Obligation Doctrine

A moral obligation arises when a party feels an ethical or conscientious duty to pay for a past favor, rescue, or kindness. As a general rule, a moral obligation alone does not constitute valid consideration .

Mills v. Wyman (1825): An adult son fell critically ill while returning from a sea voyage. A good Samaritan cared for him until the son died. The son's father subsequently wrote a letter promising to reimburse the Good Samaritan for all expenses incurred. The court held the father's promise unenforceable: the adult son was not a dependent for whom the father had a legal duty of care, the services were completed in the past, and pure moral duty cannot substitute for consideration.

Webb v. McGowin (1935) — The Material Benefit Rule: In an industrial mill, Webb was dropping a heavy wooden block to the lower floor when he realized McGowin was standing directly below. To avoid crushing McGowin, Webb fell with the block, diverting it away from McGowin but suffering permanent, crippling injuries. McGowin gratefully promised to pay Webb $15 every two weeks for the rest of Webb's life. McGowin paid until his death; his estate then refused further payments. The Alabama court enforced the promise under the material benefit rule :

The promisor received a direct, substantial material economic benefit (saving his life and physical person);
The promisee suffered significant physical injury and detriment;

The subsequent promise confirmed the obligation and eliminated the presumption of a gratuitous gift.

Restatement (Second) of Contracts § 86: Adopts the material benefit rule, stating that a promise made in recognition of a benefit previously received is binding to the extent necessary to prevent injustice, unless the benefit was conferred as a gift or the promise's value is disproportionate to the benefit received.

Illusory Promises vs. Conditional Promises

For a bilateral contract to exist, there must be mutuality of obligation —both parties must bind themselves to legal duties. If one party appears to promise something but retains complete, unfettered discretion whether to perform, the promise is illusory .

Characteristics of Illusory Promises

Unfettered Discretion: "I promise to buy your automobile for $5,000 if I decide I want it next Tuesday." This promise commits the speaker to nothing; they can walk away without breaching.

Unrestricted Cancellation at Any Time: An agreement allowing Party A to cancel the contract at any time, without notice and without consequence, renders Party A's promise illusory at common law.

Valid Non-Illusory Limitations

Promises that appear discretionary are not illusory if legal limitations constrain the promisor:

Right of Cancellation Upon Notice: An agreement granting a right to cancel upon 30 days' written notice is fully enforceable. The requirement to give notice and remain bound during that 30-day window provides legal detriment.

Satisfaction Clauses: A promise conditioned upon personal satisfaction is not illusory because the party's judgment is legally constrained by good faith (for aesthetic/artistic taste) or an objective reasonable person standard (for commercial utility).

Requirements and Output Contracts: An agreement to buy all goods a factory requires is not illusory because the buyer is bound by good faith not to purchase elsewhere.

The Pre-Existing Duty Rule & Contract Modifications

Under the common law, performing or promising to perform an act that the promisee is already legally obligated to do does not constitute valid consideration. This is the pre-existing duty rule .

The Common Law Doctrine

Alaska Packers' Ass'n v. Domenico (1902): Fishermen agreed in San Francisco to sail to Alaska and pack salmon for the season at a specified rate. Once in remote Alaska, with the fishing season underway and no replacement labor available, the fishermen struck and demanded an immediate wage increase. The superintendent signed a modified agreement agreeing to the higher wages. At the end of the season, the company refused to pay the additional sum. The Ninth Circuit held the modification void for lack of consideration: the fishermen promised only the exact services they were already contractually bound to deliver. Common Law Pre-Existing Duty:

[Existing Obligation to Perform Work] + [Promise to Pay More Money]
= NO NEW DETRIMENT = UNENFORCEABLE MODIFICATION
Exceptions to the Common Law Pre-Existing Duty Rule

A modification of an existing common law contract is valid despite the pre-existing duty rule if:

Unforeseen Difficulties (Restatement (Second) § 89): The modification is fair and equitable in view of circumstances not anticipated by the parties at the time the contract was made. These must be extraordinary, burdensome conditions going beyond standard market price fluctuations (e.g., unexpected subsurface quicksand or solid granite in an excavation).

Altered or Different Performance: The promisee gives up something new or does something different in kind, however slight (e.g., agreeing to pay earlier than required, changing the delivery method, or adding an extra task).

Pre-Existing Duty to a Third Party (Restatement (Second) § 73): Under modern contract law, a promise by a third party (Party C) to pay Party B an additional sum if Party B completes Party B's existing contract with Party A is supported by consideration . While Party B already owed the duty to Party A, Party B owed no duty to Party C; conferring that direct right onto Party C constitutes legal value.

Mutual Rescission and New Contract: The parties completely tear up and extinguish the original contract, releasing each other from all unperformed executory duties, and then execute a brand-new contract.

Contract Modifications: Common Law vs. UCC § 2-209(1)

The Uniform Commercial Code fundamentally departs from the common law pre-existing duty rule for contracts involving the sale of goods.

UCC § 2-209(1) Rule
UCC § 2-209(1): "An agreement modifying a contract within this Article needs no consideration to be binding."

Under Article 2, an enforceable modification does not require new consideration, additional duties, or unforeseen emergencies. Instead, the UCC protects the parties through the obligation of good faith :

Good Faith Standard (UCC § 1-304 & § 2-103): The party requesting the modification must act with honesty in fact and observe reasonable commercial standards of fair dealing in the trade .

Legitimate Commercial Reason: The modification must be motivated by a legitimate business reason, such as a sharp market price increase, sudden raw material shortage, or transportation crisis. Economic extortion or bad-faith coercion (threatening breach without legitimate commercial justification) renders the modification void.

Comparison Table: Contract Modifications

Feature Common Law (Services / Real Property) UCC § 2-209(1) (Sale of Goods)

Consideration Required? Yes. Fresh consideration is mandatory unless an exception applies. No. No new consideration is required.

Governing Standard Pre-existing duty rule; Restatement § 89 (unforeseen difficulties). Good faith and observance of reasonable commercial standards.

Market Price Shift Ordinary price increases do not excuse consideration. Substantial market shifts provide a legitimate commercial reason.

Oral Modification Binding if supported by consideration (unless within Statute of Frauds). Binding without consideration; "No Oral Mod" clauses enforceable (§ 2-209(2)).

Remedy for Extortion Defense of lack of consideration or economic duress. Defense of bad faith and lack of good faith under UCC § 1-304.

FYLSE Exam Scenarios & Doctrinal Traps
Scenario 1: The Subcontractor Granite Dilemma

Hypothetical: A foundation contractor contracted to excavate a building site for $100,000. While digging, the contractor struck a massive subterranean granite formation that was completely omitted from official geological soil surveys. The contractor notified the developer that blasting through the unexpected formation would cost an additional $40,000 and that work would halt unless the developer agreed to the increase. The developer agreed in writing to pay $140,000. After the excavation was completed, the developer tendered only $100,000. Analysis: Because this is a service contract, common law applies. Under Restatement (Second) § 89, the modification is enforceable without fresh consideration because the granite formation was an extraordinary, unforeseen difficulty that makes the modification fair and equitable.

Scenario 2: The Part-Payment of a Debt ( Foakes v. Beer / Pinnel's Case)

Hypothetical: Debtor owes Creditor an undisputed, matured, liquidated debt of $10,000. Creditor tells Debtor: "If you pay me $7,000 right now, I will forgive the remaining $3,000 balance." Debtor pays $7,000 cash. Creditor then sues Debtor for $3,000. Analysis: Under the common law pre-existing duty rule, Debtor already had an existing legal duty to pay the full $10,000. Paying a lesser sum on a liquidated, matured debt is not consideration for the creditor's promise to release the balance. Creditor recovers the remaining $3,000 unless Debtor gave different performance (e.g., paying before the due date, paying in a different place, or adding a tangible chattel).