Skip Navigation Links

Affirmative Defenses

Legal Defenses to a Lawsuit 


En Español

When answering a lawsuit, defendants can present information or evidence that reduces or eliminates their liability. These are called "affirmative defenses."  Affirmative defenses are the legal reason why, even if everything happened just as described by the plaintiff, the defendant should not be held liable.

All defenses, supporting facts, and "new matters" constituting a defense must be included in the Answer (Code of Civil Procedure §431.30(b)(2)). If you do not raise a particular defense in your Answer, you will be prohibited from using or raising it later on (see Ekstrom v. Marquesa at Monarch Beach Homeowners Ass'n, 168 Cal. App. 4th 1111 (2008) (available online at

There are hundreds of available affirmative defenses - too many to list here. There are some affirmative defenses that may fit most case types and others that are specific to particular causes of action. A few of the common affirmative defenses that may apply to most types of cases include:

Running of the Statute of Limitations. California Code of Civil Procedure §§312-366.3 sets time limits for filing most types of lawsuits. This defense may apply if the complaint was filed after the time period allowed by law.
Example: Under California Law, cases for breach of written contract must be started within 4 years from the date the contract is breached. If a creditor sues you, and it has been more than 4 years since your last payment or other activity on the credit card, you may raise this defense. The creditor has missed the statue of limitations for this type of case.

Failure to State a Cause of Action. A complaint must include at least one cause of action, which is the legal theory upon which the lawsuit is based. Each cause of action has certain elements that must be included in the complaint and proved at trial.  This defense may apply if the plaintiff has failed to state the necessary elements in their cause(s) of action.
Example: In a complaint for injury for breach of contract, the plaintiff must allege several elements: that a contract existed; that the plaintiff performed his or her part of the contract; that the defendant did not perform his or her part of the contract; and that the plaintiff was damaged by the defendant's breach of the contract. If the plaintiff does not state one or more of these elements in his complaint, the defendant may raise this defense.

Laches. Plaintiffs are required to act promptly to enforce their rights. This defense may apply if the plaintiff waited a long time to file the lawsuit without a good reason for the delay, and if the delay made it difficult for you to defend yourself, or causes you increased damages. The defense of laches is only available in cases where equitable relief, such as an injunction, is sought. This defense is not available in cases where the plaintiff is seeking money damages.
Example: The plaintiff intends to sue the defendant, but knows that the defendant has a very strong witness. The plaintiff also knows that the defendant's witness is terminally ill, with just a year to live. The plaintiff, without good cause, waits until this witness dies to file the case, harming the defendant's ability to defend the matter. In this case, laches could apply because the plaintiff waited unreasonably long to file suit, and the defendant's ability to defend the case was severely prejudiced as a result.

Waiver and Estoppel. These two defenses are closely related. They are based on the concept that if the plaintiff says one thing, and the defendant relies upon it, but then the plaintiff does another thing, the plaintiff may be held to what they said or did first.
Example:During a phone negotiation, a representative from the credit card company tells you that the remaining balance on an account has been forgiven. Even if this forgiveness is not documented in writing, you may use this promise as a defense if the creditor later sues you for this debt.

Failure to Mitigate Damages. A Plaintiff cannot collect money from a defendant if they could have reasonably prevented or reduced their damages. This defense may apply if the plaintiff acted in a way to make the damages worse, or refused to act reasonably to minimize the damages.
Example: You sign a one year lease, but have to move for work just a few weeks later. The landlord makes no effort to find a new tenant, and at the end of the year sues you for the entire year's worth of missed rent payments. You may have a defense of Failure to Mitigate Damages because the landlord made no effort to minimize his losses by looking for a new tenant.

Unjust Enrichment. Absent a law that establishes the amount of damages (statutory damages), or where the parties agree in advance on the amount of damages (liquidated damages), a plaintiff may only recover compensatory damages for the amount of harm experienced. If a plaintiff seeks to recover more than what is owed, more than required to compensate for the harm experienced, or more than is permitted under statute or the contract, the plaintiff's recovery could be limited by this defense.
Example: If a plaintiff loaned $10,000 without interest, and $5,000 is paid back before the contract was breached, the plaintiff cannot seek damages in excess of the $5,000 (but could ask for pre-judgment interest from the date the Complaint is filed).

Quantum Meruit. If a plaintiff and defendant do not agree upon the price of a good or service before it is provided, or if the goods or service are only partly provided, the plaintiff's recovery is limited to the fair market value of the goods or services actually provided.
: If a contractor leaves the job without completing it, and then sues for payment, the judgment would be limited by this defense to the fair value of the work performed and materials provided. Likewise, if emergency room services are provided to a patient without the opportunity to review and negotiate the price, the hospital's recovery might be limited to the fair value of the services performed if the amount billed exceeds the services' fair market value.

Lists of common affirmative defenses for several popular causes of action can be found from these websites:


Motor Vehicle:

Breach of Contract:

Unlawful Detainer:

There are many more affirmative defenses that may apply to your case. You will need to research each cause of action in your case to determine if you have any affirmative defenses. To research possible affirmative defenses for your case, see:

California Affirmative Defenses KFC 995 .S38
Electronic Access:  On the Law Library's computers, using WestlawNext.

California Civil Courtroom Handbook and Desktop Reference KFC 995 .Z9 T46
Discussion §§12:8 – 12:11

California Civil Practice: Procedure Vol. 2, Chap. 9. KFC 995 .A65 B3
Discussion §§9:74 – 9:115
Electronic Access:  On the Law Library's computers, using WestlawNext.

California Civil Procedure Before Trial Vol. 2, Chap. 25.  KFC 995 .C34
Discussion §§25:30 – 25:64
Electronic Access:  On the Law Library's computers, using OnLaw.

California Forms of Pleading and Practice Vol. 3, Chap 26 KFC 1010 .A65 C3
List of Affirmative Defenses §§26.150-26.313
Electronic Access:  On the Law Library's computers, using the Matthew Bender CD.

created 9/12 mpj