(1) Cal. Code Civ. Proc. § 431.30(b)(2) (pleading affirmative defenses), and other standard defenses. See Chapter 1 for all defenses.
(2) Statute of Limitations: Written contracts, 4 years (Cal. Code Civ. Proc. § 337) and oral contracts, 2 years. (Cal. Code Civ. Proc. § 339).
(3) Duress: “The stringent definition of duress contained in Civil Code section 1569, codifying the early common law rule, has been relaxed. . . Under the modern rule, ‘“[d]uress, which includes whatever destroys one’s free agency and constrains [her] to do what is against [her] will, may be exercised by threats, importunity or any species of mental coercion [citation] . . . .”’ It is shown where a party ‘intentionally used threats or pressure to induce action or nonaction to the other party's detriment.’ The coercion must induce the assent of the coerced party, who has no reasonable alternative to succumbing.” See In re Marriage of Baltins, 212 Cal. App. 3d 66, 84 (1989); see Cal. Civ. Code §§1567(1) & 1569.
(4) Sufficiency of Pleading: “While the allegation of performance ‘can be satisfied by allegations in general terms’ . . . ‘excuses must be pleaded specifically.’” Durell v. Sharp Healthcare, 183 Cal. App. 4th 1350, 1367 (2010).
(5) Statute of Frauds: Civil Code section1624 codifies the Statute of Frauds and identifies the types of contracts that must be in writing to be enforceable. See Chapter 1 for further explanation of this defense.
(6) Unclean Hands: The California Court of Appeals has concluded that “the equitable defense of unclean hands is available in this state as a defense to a legal action.” Fiberboard Paper Prods. Corp. v. E. Bay Union of Machinists, 227 Cal. App. 2d 675, 728 (1964); see also Cal. Civ. Code § 3517.
(7) Failure of Consideration: “‘[F]ailure of consideration is the failure to execute a promise, the performance of which has been exchanged for performance by the other party.’” FPI Dev., Inc. v. Nakashima, 231 Cal. App. 3d 367, 398 (1991).
(8) Impossibility: “[W]here performance depends upon the existence of a given thing, and such existence was assumed as the basis of the agreement, performance is excused to the extent that the thing ceases to exist or turns out to be nonexistent.” Mineral Park Land Co. v. Howard, 172 Cal. 289, 291 (1916). However, “where a party has agreed, without qualification, to perform an act which is not in its nature impossible of performance, he is not excused by difficulty of performance, or by the fact that he becomes unable to perform.” Id.; see Habitat Trust for Wildlife, Inc. v. City of Rancho Cucamonga, 175 Cal. App. 4th 1306, 1336 (2009). “[P]artial impossibility of performance by one party excuses the other party from performing under an agreement only if the term that cannot be performed was material to the agreement as a whole.” People v. McIntosh, 177 Cal. App. 4th 534, 545 (2009). “[T]he burden of proving impossibility of performance [i]s on the defendant.” Butler v. Nepple, 54 Cal. 2d 589, 598 (1960).
(9) Excuse of Performance: California Civil Code section 1511 provides:
The want of performance of an obligation, or of an offer of performance, in whole or in part, or any delay therein, is excused by the following causes, to the extent to which they operate:
1. When such performance or offer is prevented or delayed by the act of the creditor, or by the operation of law, even though there may have been a stipulation that this shall not be an excuse; however, the parties may expressly require in a contract that the party relying on the provisions of this paragraph give written notice to the other party or parties, within a reasonable time after the occurrence of the event excusing performance, of an intention to claim an extension of time or of an intention to bring suit or of any other similar or related intent, provided the requirement of such notice is reasonable and just;
2. When it is prevented or delayed by an irresistible, superhuman cause, or by the act of public enemies of this state or of the United States, unless the parties have expressly agreed to the contrary; or,
3. When the debtor is induced not to make it, by any act of the creditor intended or naturally tending to have that effect, done at or before the time at which such performance or offer may be made, and not rescinded before that time.
(10) Frustration of Purpose: “The elements of th[e] doctrine [of frustration of purpose] are as follows: Performance remains possible, but the fundamental reason of both parties for entering into the contract has been frustrated by an unanticipated supervening circumstance, thus destroying substantially the value of performance by the party standing on the contract.” Cutter Laboratories, Inc. v. Twining, 221 Cal. App. 2d 302, 314-15 (1963).
(11) Accord and satisfaction: Accord and satisfaction: “For the affirmative defense of accord and satisfaction to apply in disposition of an unliquidated claim, the defendant must establish: (1) that there was a ‘bona fide dispute’ between the parties, (2) that the debtor made it clear that acceptance of what he tendered was subject to the condition that it was to be in full satisfaction of the creditor's unliquidated claim, and (3) that the creditor clearly understood when accepting what was tendered that the debtor intended such remittance to constitute payment in full of the particular claim in issue. . . . A writing is not essential to an accord and satisfaction; it may be implied.” Thompson v. Williams, 211 Cal. App. 3d 566, 571 (1989); see Potter v. Pac. Coast Lumber Co., 37 Cal. 2d 592, 597 (1951); see also Cal. Civ. Code §§ 1521-1523. See Chapter 1 for further explanation of this defense.
(12) Illegality: “The consideration for a contract must be lawful. (Civ. Code, § 1607.) If any part of the consideration is unlawful the entire contract is void. (Civ. Code, § 1608.) Consideration is unlawful if it is contrary to an express provision of law, contrary to the policy of express law, though not expressly prohibited, or is otherwise contrary to good morals. (Civ. Code, § 1667.) The object of a contract is the thing which it is agreed, on the part of the party receiving the consideration, to do or not to do. (Civ. Code, § 1595.) The object must be lawful when the contract is made. (Civ. Code, § 1596.)” Russell v. Soldinger, 59 Cal. App. 3d 633, 641 (1976). Contract that are illegal are “‘(1) those contrary to express statutes; (2) those contrary to the policy of express statutes; (3) those otherwise contrary to good morals.’” Duffens v. Valenti, 161 Cal. App. 4th 434, 450 n.5 (2008) (emphasis in original).
(13) Lack of Consent: Consent or mutual assent is required regardless of whether the contract is express or implied. Division of Labor Law Enforcement v. Transpacific Transp. Co., 69 Cal. App. 3d 268, 275 (1977); see Cal. Civ. Code §§ 1565, et seq. (definition of consent and matters vitiating consent).
(14) Void Contract: “‘Void promises are not legally binding, have no legal effect, and, therefore, are not contracts.’ . . . ‘[I]f a bargain violates public policy, it is void and of no legal effect.’ . . . Void contracts cannot be ratified.” Estate of Molino, 165 Cal. App. 4th 913, 925 (2008).
(15) Voidable Contract: “‘As with any other contract where one party lacks capacity, or a necessary contractual formality has been ignored, the contract is voidable until the defect is remedied.’” Pearson v. Superior Court, 202 Cal. App. 4th 1333, 1338 (2012); see, e.g., Fam. Code, §§ 6700, et seq. (minor’s contracts are voidable).