California Bar Consideration
Last updated: May 2, 2026
Consideration questions are one of the highest-leverage areas to study for the California Bar. 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
Consideration is a bargained-for exchange in which each party incurs legal detriment (does, forbears from doing, or promises to do or forbear from something they were not previously legally obligated to do) and the promise and the detriment induce each other. Both common law and UCC Article 2 require consideration to form an enforceable contract, but the UCC dispenses with consideration for good-faith modifications of sale-of-goods contracts (UCC § 2-209(1)) and for firm offers by merchants (UCC § 2-205). Past consideration, moral obligation, and pre-existing duties are not consideration under the majority rule, though courts may enforce a promise without consideration through promissory estoppel (Restatement (Second) of Contracts § 90). California follows the majority approach but codifies consideration at Cal. Civ. Code §§ 1605–1615 and treats a written instrument as presumptive evidence of consideration (Cal. Civ. Code § 1614).
Elements breakdown
Bargained-For Exchange
The promise must induce the detriment, and the detriment must induce the promise.
- Promisor seeks the performance or return promise
- Promisee gives it in exchange for the promise
- Mutual inducement, not coincidence or gift
Common examples:
- Employer promises bonus in exchange for employee remaining one year
- Buyer promises payment in exchange for seller's promise to deliver
Legal Detriment (Benefit-Detriment Test)
Each party must do, forbear, or promise to do or forbear something they had no prior legal duty to do.
- Act, forbearance, or promise by the promisee
- Promisee was not legally obligated to perform it
- Detriment to promisee or benefit to promisor suffices
Common examples:
- Forbearing from suing on a colorable claim
- Promising not to drink alcohol until age 21
Pre-Existing Duty Rule
A promise to perform what one is already legally obligated to do is not consideration for a new promise.
- Promisor owes existing legal duty
- Promise merely repeats that duty
- No new detriment incurred
Common examples:
- Police officer cannot collect reward for arrest made on duty
- Contractor demanding more pay to finish original job (common law)
Modification Rules
Common law requires new consideration for modification; UCC § 2-209(1) does not, requiring only good faith.
- Common law: new consideration OR unforeseen difficulty exception
- UCC: good-faith modification, no new consideration needed
- Watch for no-oral-modification clauses (UCC § 2-209(2))
Common examples:
- Construction contract price increase needs new consideration at common law
- Steel-supply contract price bump enforceable under UCC if in good faith
Illusory Promise
A promise that leaves performance entirely to the promisor's unfettered discretion is not consideration because it commits to nothing.
- Promise reserves unlimited discretion
- No actual commitment to act or forbear
- Implied good-faith obligations may save requirements/output contracts
Common examples:
- 'I'll buy as much as I want' — illusory
- Requirements contract — saved by implied good-faith demand (UCC § 2-306)
Promissory Estoppel (Substitute for Consideration)
A promise reasonably expected to induce reliance, which does induce substantial reliance, is enforceable to prevent injustice (Rest. 2d § 90).
- Promise made
- Promisor reasonably expected reliance
- Promisee actually and reasonably relied
- Injustice avoidable only by enforcement
Common examples:
- Charitable subscription pledges
- Employer's promise of pension causing employee to retire
Past Consideration & Moral Obligation
A promise to pay for an act already performed is generally not supported by consideration; California recognizes a narrow exception by statute.
- Act preceded promise
- No bargain at time of act
- Majority: unenforceable; minority/Cal. Civ. Code § 1606: enforceable if moral obligation arose from pre-existing legal duty
Common examples:
- 'Thanks for saving my barn — I'll pay you $1,000' — unenforceable
- Promise to pay debt barred by statute of limitations — enforceable in writing
Common patterns and traps
The Pre-Existing Duty Disguise
The fact pattern presents what looks like a fresh promise but the promisee was already legally bound to perform. Bar examiners hide the pre-existing duty in an earlier paragraph or a passing reference to a prior contract or public office. The trap exploits candidates who analyze the new promise in isolation without checking whether the promisee already owed the performance.
An answer choice that says 'enforceable, because the parties exchanged mutual promises' without addressing the prior contractual or statutory duty already requiring the promisee to perform.
The Common-Law/UCC Switch
The fact pattern involves a contract modification, and the candidate must first classify whether the contract is for goods (UCC) or services/real estate (common law) before applying the consideration rule. Common law demands new consideration; UCC § 2-209(1) does not, requiring only good faith. Bar items often use mixed contracts where the predominant-purpose test is decisive.
An answer choice that demands 'new consideration' for a price increase in a sale-of-goods contract, ignoring UCC § 2-209(1).
The Illusory Promise Mirage
One party's promise contains words like 'if I want,' 'as I see fit,' or 'subject to my approval,' creating the appearance of a bargain without any real commitment. The trap also runs in reverse: candidates label requirements or output contracts illusory, missing that the implied good-faith obligation under UCC § 2-306 supplies the consideration.
An answer choice that calls a requirements contract 'unenforceable for lack of mutuality' without recognizing the implied good-faith limit on quantity.
The Past Consideration Sympathy Trap
The promisor makes a promise out of gratitude or moral sense after the promisee has already conferred a benefit. Sympathetic facts (rescue, life-saving) push candidates to enforce the promise, but the majority rule denies consideration for past acts. California recognizes a narrow statutory exception (Cal. Civ. Code § 1606) only where a pre-existing legal duty supports the moral obligation.
An answer choice enforcing a promise to pay a rescuer 'because the promisor felt morally obligated' without analyzing bargained-for exchange.
The Promissory Estoppel Rescue
When consideration fails, a candidate must consider whether promissory estoppel under Restatement (Second) § 90 enforces the promise based on reasonable reliance. The trap is failing to spot estoppel as a backup theory after concluding no consideration exists, or misapplying it where reliance was unforeseeable or unreasonable.
An answer choice that says 'unenforceable for lack of consideration' and ignores substantial detrimental reliance that a court would protect under § 90.
How it works
Think of consideration as the law's gatekeeping device for separating enforceable bargains from gratuitous promises. The hardest part on the bar is not reciting the rule but spotting that what looks like a deal is actually a gift, a pre-existing duty, or an illusory commitment. Suppose Reyes promises Liu $5,000 if Liu finishes painting Reyes's barn — and Liu is already under contract to paint it for $4,000. Liu's promise to do what she already owes is not consideration for the extra $1,000 under the common law pre-existing duty rule, so the modification fails unless an unforeseen-difficulty exception applies. Flip the facts to a sale of paint between merchants and the UCC's good-faith modification rule under § 2-209(1) makes the same price bump enforceable without new consideration. The bar tests this inflection point relentlessly — identify the governing body of law (common law vs. UCC) before you reach for the consideration analysis.
Worked examples
Will Reyes succeed in collecting the additional $25,000?
- A Yes, because the parties agreed to the modification in writing and a written instrument is presumptive evidence of consideration.
- B Yes, because under UCC § 2-209(1) a good-faith modification needs no new consideration.
- C No, because Reyes was already under a pre-existing duty to complete the construction for $180,000 and gave no new consideration for the price increase. ✓ Correct
- D No, because the modification was the product of economic duress and is voidable regardless of consideration.
Why C is correct: This is a construction services contract governed by the common law, not the UCC. Under the common law pre-existing duty rule, a promise to perform what one is already legally obligated to do is not consideration for a new promise. Reyes was already bound to build the guest house for $180,000 and offered nothing new in exchange for the additional $25,000. No unforeseen-difficulty exception applies because soft soil is an ordinary construction risk Reyes assumed.
Why each wrong choice fails:
- A: While Cal. Civ. Code § 1614 makes a writing presumptive evidence of consideration, that presumption is rebuttable and is overcome where, as here, the record affirmatively shows the promisee was performing only a pre-existing duty. The writing does not manufacture consideration that does not exist. (The Pre-Existing Duty Disguise)
- B: UCC § 2-209(1) applies only to contracts for the sale of goods. This is a construction services contract governed by common law, which requires new consideration for modification absent an unforeseen-difficulty exception. (The Common-Law/UCC Switch)
- D: Economic duress might be a valid defense on different facts, but the call asks whether Reyes will succeed, and the cleaner, dispositive ground is failure of consideration under the pre-existing duty rule. The question signals the consideration analysis as the operative issue.
How should the court rule on Liu Properties' defense?
- A For Liu Properties, because a promise to buy 'all that I require' commits the buyer to no determinate quantity and is therefore illusory.
- B For Liu Properties, because the contract lacked mutuality of obligation since Mendoza was bound to deliver but Liu Properties was free to walk away.
- C For Mendoza, because UCC § 2-306 imposes a good-faith obligation on Liu Properties to buy its actual requirements, and that good-faith limitation supplies the consideration. ✓ Correct
- D For Mendoza, because Liu Properties' acceptance of three months of deliveries created a course-of-performance obligation to continue purchasing for the contract term.
Why C is correct: Requirements contracts are governed by UCC § 2-306, which is enforceable because the buyer's discretion is limited by the implied obligation of good faith and any stated estimate or normal prior requirements. That good-faith limitation supplies the bargained-for detriment on the buyer's side, defeating the illusory-promise defense. Liu Properties' decision to switch suppliers to chase a lower price violates the good-faith requirement and constitutes breach.
Why each wrong choice fails:
- A: This answer applies the illusory-promise doctrine without recognizing UCC § 2-306, which expressly validates requirements contracts by reading in a good-faith quantity term. The 'all I require' formulation is a textbook enforceable requirements contract, not an illusory one. (The Illusory Promise Mirage)
- B: The mutuality-of-obligation argument is the same illusory-promise objection in different dress and fails for the same reason — UCC § 2-306's good-faith floor supplies the buyer's commitment. Modern contract law has largely rejected mutuality as a separate doctrine apart from consideration analysis. (The Illusory Promise Mirage)
- D: Course of performance can inform interpretation of an ambiguous term but cannot itself create a binding obligation where none existed at formation. The contract was enforceable from day one because of UCC § 2-306, not because of subsequent performance.
Is the written promise enforceable?
- A Yes, because Hassan suffered substantial physical injury in reliance on Okonkwo's gratitude, satisfying promissory estoppel.
- B Yes, because Cal. Civ. Code § 1614 treats a written instrument as presumptive evidence of consideration.
- C No, because Hassan's act preceded the promise and past consideration is not consideration under the majority rule. ✓ Correct
- D No, because rescuers have a pre-existing legal duty to render aid in emergencies, so Hassan gave no new detriment.
Why C is correct: This is the classic past-consideration trap. Hassan's heroic act was completed before Okonkwo made any promise, so there was no bargained-for exchange — Okonkwo's promise was made in gratitude, not in exchange for the rescue. Under the majority rule, past consideration is not consideration. California's narrow statutory exception in Cal. Civ. Code § 1606 applies only where the moral obligation arose from a pre-existing legal duty (such as a debt barred by the statute of limitations), which is not present on these facts.
Why each wrong choice fails:
- A: Promissory estoppel requires reliance induced by the promise, but Hassan's burns occurred before the promise was made, so the reliance element is impossible to satisfy. You cannot rely on a promise that does not yet exist. (The Promissory Estoppel Rescue)
- B: The Cal. Civ. Code § 1614 presumption is rebuttable, and the facts affirmatively show the promise was made for a past act with no bargain — that defeats the presumption rather than confirming consideration. A writing cannot supply consideration that the substantive transaction lacks. (The Past Consideration Sympathy Trap)
- D: This misstates the law: California, like most jurisdictions, does not impose a general duty to rescue on bystanders. Even if it did, that fact would cut against Hassan having given consideration, but the controlling reason the promise fails is the past-consideration doctrine, not pre-existing duty. (The Pre-Existing Duty Disguise)
Memory aid
BARGAIN: Bargained-for, Adequate (legal sufficiency, not economic equivalence), Reciprocally induced, Genuine detriment, Already-owed duty doesn't count, Illusory promises fail, New consideration needed at common law for modification.
Key distinction
The decisive question is almost always whether the parties' obligations were reciprocally induced (consideration) versus whether one party gave something in gratitude, pursuant to a pre-existing duty, or as a conditional gift. If you can rephrase one side as 'I was going to do that anyway' or 'thanks for what you already did,' there is no consideration.
Summary
Consideration is bargained-for legal detriment on both sides, and the bar tests it by hiding pre-existing duties, past acts, illusory promises, and the common-law/UCC modification split inside otherwise innocuous fact patterns.
Practice consideration adaptively
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Start your free 7-day trialFrequently asked questions
What is consideration on the California Bar?
Consideration is a bargained-for exchange in which each party incurs legal detriment (does, forbears from doing, or promises to do or forbear from something they were not previously legally obligated to do) and the promise and the detriment induce each other. Both common law and UCC Article 2 require consideration to form an enforceable contract, but the UCC dispenses with consideration for good-faith modifications of sale-of-goods contracts (UCC § 2-209(1)) and for firm offers by merchants (UCC § 2-205). Past consideration, moral obligation, and pre-existing duties are not consideration under the majority rule, though courts may enforce a promise without consideration through promissory estoppel (Restatement (Second) of Contracts § 90). California follows the majority approach but codifies consideration at Cal. Civ. Code §§ 1605–1615 and treats a written instrument as presumptive evidence of consideration (Cal. Civ. Code § 1614).
How do I practice consideration questions?
The fastest way to improve on consideration 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 California Bar; 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 consideration?
The decisive question is almost always whether the parties' obligations were reciprocally induced (consideration) versus whether one party gave something in gratitude, pursuant to a pre-existing duty, or as a conditional gift. If you can rephrase one side as 'I was going to do that anyway' or 'thanks for what you already did,' there is no consideration.
Is there a memory aid for consideration questions?
BARGAIN: Bargained-for, Adequate (legal sufficiency, not economic equivalence), Reciprocally induced, Genuine detriment, Already-owed duty doesn't count, Illusory promises fail, New consideration needed at common law for modification.
What's a common trap on consideration questions?
Treating moral obligation or past act as consideration
What's a common trap on consideration questions?
Missing the UCC § 2-209(1) good-faith modification rule
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