The grounds for a motion to strike in California come from Section 436 of the Code of Civil Procedure, which lets a court remove two kinds of material from a pleading: matter that is irrelevant, false, or improper, and any part of a pleading that was not drafted or filed in conformity with California law, a court rule, or a prior court order.1California Legislative Information. California Code of Civil Procedure 436 The court can act on a party’s motion or on its own initiative, at any point in the case.
The Two Statutory Grounds Under Section 436
Everything else about a standard motion to strike flows from those two categories. The first covers content: something in the pleading is irrelevant, false, or improper and shouldn’t be there. The second covers form and compliance: the pleading, or a part of it, violates a statute, a rule of court, or an order the court has already made in the case.1California Legislative Information. California Code of Civil Procedure 436
One important limit sits inside the statute’s text. The grounds for a motion to strike must appear on the face of the challenged pleading or from facts the court can judicially notice. You can’t attach declarations or outside evidence to prove that an allegation is false; the defect has to be visible from the pleading itself.
What Qualifies as Irrelevant, False, or Improper
Within the first Section 436 category, most motions target one of a few recurring problems.
False or unsupported allegations. These are claims inserted into a pleading that are demonstrably untrue on the face of the document.
Irrelevant or prejudicial material. Language that has no connection to the actual dispute but could sway a jury or muddy the issues, such as inflammatory characterizations of a party, fits here.
Legal conclusions dressed up as facts. California pleadings are supposed to contain factual allegations, not bare legal conclusions. A complaint that says “defendant acted negligently” without any underlying facts is offering a conclusion, and that kind of language is a standard target.
What Qualifies as Noncompliant with Law or Court Order
The second Section 436 category is procedural. If a filing violates a statute, a rule of court, or an order the court has already entered, the offending portion can be stricken. A common example: the court has already dismissed a claim, and the opposing party tries to slip it back into an amended pleading. A motion to strike is the right response.1California Legislative Information. California Code of Civil Procedure 436
What You Cannot Use as Grounds
Two limits are worth knowing before you draft anything.
“Redundant” isn’t in the statute. Section 436 addresses false matter, not repetitive matter. A motion arguing that allegations are simply duplicative won’t find support in the statutory text. That distinction matters because federal Rule 12(f) does list “redundant” as a ground, and readers accustomed to the federal rule often assume California mirrors it.
Extrinsic evidence isn’t allowed. Because the grounds must appear on the face of the pleading or from judicially noticeable facts, a motion to strike is not the place to litigate what actually happened. If the material looks fine on paper but you have proof it’s false, that’s a fight for summary judgment or trial.
Which Pleadings Can Be Challenged
Section 435 defines the documents you can attack. A “pleading” for these purposes means a complaint, cross-complaint, answer, or demurrer. Any party may move to strike the whole or any part of these filings within the time allowed to respond.2Justia. California Code of Civil Procedure 435-437 Filing the motion instead of an answer also extends your time to respond and protects you from default while the motion is pending.
Meet and Confer Before You File
Before filing, California law requires the moving party to contact the other side and try to resolve the dispute informally. Under CCP Section 435.5, you must meet and confer in person, by phone, or by video with the party who filed the challenged pleading.3California Legislative Information. California Code of Civil Procedure 435.5 During that conversation you have to identify each specific allegation you believe should be stricken and explain the legal basis for each objection. The other side should explain why the pleading is sufficient or how it could be amended.
The meet and confer must happen at least five days before the filing deadline. If you can’t manage it in time, filing a declaration under penalty of perjury describing your good-faith effort earns an automatic 30-day extension. When you eventually file the motion, you must attach a declaration describing how you met and conferred and stating that no agreement was reached, or that the other party refused to participate.3California Legislative Information. California Code of Civil Procedure 435.5
The statute says a court’s finding that the meet and confer process was insufficient is not itself grounds to grant or deny the motion. Still, judges notice, and a solid effort improves your footing.
Anti-SLAPP: A Separate Set of Grounds
California also has a “special motion to strike” under the anti-SLAPP statute, CCP Section 425.16, and its grounds have nothing to do with Section 436. “SLAPP” stands for Strategic Lawsuit Against Public Participation, meaning a suit filed to burden someone with litigation costs for exercising free speech rights rather than to win on the merits.
The grounds are activity-based. A defendant must show that the lawsuit arises from protected activity, meaning conduct in furtherance of the right of petition or free speech in connection with a public issue. The statute defines protected activity to include statements made in official proceedings, statements connected to issues under review by a government body, statements in a public forum about a public issue, and other conduct furthering free speech or petition rights on a matter of public interest. If the defendant clears that first step, the plaintiff must then show a probability of prevailing on the claim, supported by admissible evidence, or the claim is stricken.4California Legislative Information. California Code of Civil Procedure 425.16
Two features raise the stakes. A prevailing defendant is entitled to a mandatory award of attorney fees and costs; the only question is amount. Fees run the other way if the court finds the anti-SLAPP motion was frivolous or filed solely to cause delay. And discovery automatically freezes the moment an anti-SLAPP motion is filed, staying in place until the court rules, unless a party shows good cause to lift the stay for specific discovery.4California Legislative Information. California Code of Civil Procedure 425.16
Federal Rule 12(f) Is Different
If your case is in federal court, the grounds shift. Federal Rule of Civil Procedure 12(f) allows a court to strike an insufficient defense or any redundant, immaterial, impertinent, or scandalous matter from a pleading.5Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Defenses and Objections: When and How Presented The court can act on its own or on a party’s motion filed before responding to the pleading, or within 21 days of service if no response is required. Two differences matter for planning. Rule 12(f) expressly includes “redundant” material, which Section 436 does not. And federal courts treat Rule 12(f) motions as disfavored: because pleadings are read in the light most favorable to the non-moving party, material is “immaterial” only if it has no bearing on the controversy, and any doubt defeats the motion. California’s Section 436 gives judges broader discretion, which is part of why the motion is a more practical tool in state litigation.