California Civil Jury Instructions (CACI)
331. Affirmative Defense—Bilateral Mistake
[Name of defendant] claims that there was no contract because both parties were mistaken about [insert description of mistake]. To succeed, [name of defendant] must prove both of the following:
1. That both parties were mistaken about [insert description of mistake]; and
2. That [name of defendant] would not have agreed to enter into this contract if [he/she/it] had known about the mistake.
If you decide that [name of defendant] has proved both of the above, then no contract was created.
New September 2003
Directions for Use
This instruction does not contain the requirement that the mistake be material to the contract because the materiality of a representation is a question of law. (Merced County Mutual Fire Insurance Co. v. State of California (1991) 233 Cal.App.3d 765, 772 [284 Cal.Rptr. 680].) Accordingly, the judge would decide whether an alleged mistake was material, and that mistake would be inserted into this instruction.
If the mistake is one of law, this may not be a jury issue.
Sources and Authority
- The Civil Code provides that consent is not free when obtained through duress, menace, fraud, undue influence, or mistake, and is deemed to have been so obtained when it would not have been given but for such fraud or mistake. (Civ. Code, §§ 1567, 1568.)
- Civil Code section 1576 provides: “Mistake may be either of fact or law.”
- Civil Code section 1577 provides the following definition of mistake of fact:
Mistake of fact is a mistake, not caused by the neglect of a legal duty on the part of the person making the mistake, and consisting in:
1. An unconscious ignorance or forgetfulness of a fact past or present, material to the contract; or,
2. Belief in the present existence of a thing material to the contract, which does not exist, or in the past existence of such a thing, which has not existed.
- Civil Code section 1578 defines mistake of law:
Mistake of law constitutes a mistake, within the meaning of this Article, only when it arises from:
1. A misapprehension of the law by all parties, all supposing that they knew and understood it, and all making substantially the same mistake as to the law; or,
2. A misapprehension of the law by one party, of which the others are aware at the time of contracting, but which they do not rectify.
- Section 20(1) of the Restatement Second of Contracts provides:
(1) There is no manifestation of mutual assent to an exchange if the parties attach materially different meanings to their manifestations and
(a) neither party knows or has reason to know the meaning attached by the other; or
(b) each party knows or each party has reason to know the meaning attached by the other.
- A mistake of fact may be urged as a defense to an action upon a contract only if the mistake is material to the contract. (Edwards v. Lang (1961) 198 Cal.App.2d 5, 12 [18 Cal.Rptr. 60].)
1 Witkin, Summary of California Law (10th ed. 2005) Contracts, §§ 256–275
17 California Forms of Pleading and Practice, Ch. 215, Duress, Menace, Fraud, Undue Influence, and Mistake, §§ 215.50–215.57, 215.140 (Matthew Bender)
9 California Points and Authorities, Ch. 92, Duress, Menace, Fraud, Undue Influence, and Mistake, § 92.90 et seq. (Matthew Bender)
27 California Legal Forms, Ch. 77, Discharge of Obligations, § 77.350 (Matthew Bender)
1 Matthew Bender Practice Guide: California Contract Litigation, Ch. 8, Seeking or Opposing Equitable Remedies in Contract Actions, 8.24
1 Matthew Bender Practice Guide: California Contract Litigation, Ch. 16, Attacking or Defending Existence of Contract—Mistake, 16.08, 16.09, 16.11, 16.18