Terms stated orally or in writing

Terms inferred from conduct and circumstances

Not a true contract; remedy to prevent unjust enrichment

No legal effect from the start

One party may affirm or avoid (e.g., minor, duress)

Agreement exists but cannot be enforced (e.g., Statute of Frauds not met)

Fully performed

Performance still owed

Promise for a promise

Promise in exchange for performance

Clear intent to contract

Definite and certain terms

Communication to the offeree

Invitations to negotiate vs offers

Unconditional assent to offer terms

Mirror image rule (common law)

UCC approach (sale of goods)

Methods of acceptance

Timing and communication rules

Promise, act, or forbearance exchanged

Legal detriment or benefit (traditional framing)

Past consideration (generally not valid)

Preexisting duty rule

Illusory promises

Common law: generally requires new consideration

UCC: modifications allowed without consideration if in good faith

Clear promise

Reasonable, foreseeable reliance

Actual reliance

Injustice can be avoided only by enforcement

Enforceability depends on definiteness and expressed intent

UCC gap-fillers for goods (price, delivery, etc.)

Reasonable terms inferred from trade usage/course of dealing/course of performance

Essential terms missing with no objective basis to supply them

Fully integrated vs partially integrated

Prior or contemporaneous external terms that contradict a final writing

Clarifying ambiguity

Showing fraud, duress, mistake, illegality

Showing conditions precedent to effectiveness

Subsequent modifications

Express terms > course of performance > course of dealing > usage of trade

Generally voidable at minor’s option

Necessaries exception (liable for reasonable value)

Ratification upon reaching majority

Cognitive inability to understand or inability to act reasonably + knowledge by other party

Voidable if inability to understand and other party had reason to know

Fraudulent vs negligent vs innocent

Requires material misstatement and reliance

Remedies may include rescission and damages (depending)

Duty to disclose in certain relationships or when correcting prior statements

Threat + no reasonable alternative + causation

Economic duress (improper threat affecting assent)

Unfair persuasion in a relationship of trust or dependence

Procedural unconscionability (unfair process)

Substantive unconscionability (unfair terms)

Remedies

Crimes/torts, licensing violations, gambling (varies), usury (varies)

Non-compete agreements (must be reasonable in scope/duration/geography)

Exculpatory clauses (limits for negligence; often not for intentional harm/gross negligence)

Contracts affecting family law or public rights (often limited)

Contracts for sale of land/real property interests

Contracts that cannot be performed within one year

Suretyship (promise to answer for another’s debt)

Marriage-related promises (in some jurisdictions)

Sale of goods over the UCC threshold (often $500; may vary)

Identifies parties

Subject matter and essential terms

Signed by party to be charged (the one being sued)

Part performance (often for land)

Admission in court (UCC goods)

Specially manufactured goods (UCC)

Merchant confirmation rule (UCC between merchants)

Promissory estoppel (limited/varies)

Waiver, estoppel, prevention, forfeiture avoidance

When beneficiary can enforce

Most contractual rights unless prohibited or materially changing obligor’s risk

Anti-assignment clauses (effect varies)

Personal services (often non-assignable)

Personal skill/trust, special reliance, contract prohibits

Material vs minor breach

Treat as breach, suspend performance, seek assurances

Destruction of subject matter, death/incapacity (personal services)

Extreme and unforeseen difficulty or cost

Principal purpose substantially frustrated by unforeseen event

Contract terms, foreseeability, and assumption of risk

Rescission, release, accord and satisfaction, novation

Bankruptcy (may discharge some obligations)

Direct damages (benefit of bargain)

Consequential damages (foreseeable losses)

Incidental damages (costs to deal with breach)

Reimburse expenses incurred in reliance

Prevent unjust enrichment; value conferred

Enforceable if reasonable forecast and not a penalty

Breach with no provable loss

Generally not available for pure contract breach (exceptions tied to tort/egregious conduct)

Often for unique goods/real property

Not typical for personal services

Enforcing negative covenants (e.g., non-disclosure, non-compete if reasonable)

Correct writing to reflect true agreement (mistake/fraud)

Undo contract and restore parties

Merchantability

Fitness for a particular purpose