A motion to strike is a formal request asking a judge to remove specific material from a pleading or from the trial record. In federal civil cases, Rule 12(f) of the Federal Rules of Civil Procedure governs the version aimed at pleadings, while a separate form of the same motion is used at trial to remove witness testimony or exhibits.1Legal Information Institute. Motion to Strike Courts treat it as a strong remedy and grant it only when the challenged material clearly has no business being in the case.
Unlike a motion to dismiss, which attacks an entire claim or lawsuit, a motion to strike is surgical. It removes particular allegations, defenses, or counterclaim language while leaving the rest of the pleading intact. A judge can also strike material on the court’s own initiative under Rule 12(f), without waiting for a party to ask.2Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Section: (f) Motion to Strike
Grounds for Striking Material From a Pleading
Rule 12(f) authorizes a court to strike two things from a pleading: an insufficient defense, or any matter that is redundant, immaterial, impertinent, or scandalous.2Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Section: (f) Motion to Strike Each term carries a specific meaning.
- Redundant material repeats something already stated elsewhere in the pleading and adds nothing.
- Immaterial allegations have no bearing on the legal issues. They may be true but do not help resolve any claim or defense.
- Impertinent content does not relate to the matters at issue, often pulled in from outside the dispute.
- Scandalous allegations are highly derogatory or inflammatory and serve no legitimate purpose. The qualifier matters: unflattering content can stay if it genuinely bears on the case.
- An insufficient defense is an affirmative defense that fails as a matter of law even if every fact alleged is accepted as true. A statute-of-limitations defense that pleads dates showing the deadline has not actually run is an example.
Courts set a high bar. A motion to strike is generally denied unless the challenged language has no possible connection to the controversy and could cause real prejudice. When relevance depends on facts still in dispute, judges tend to leave the material in rather than strike it prematurely.
Pleadings vs. Trial Testimony
The same name covers two different procedures. A Rule 12(f) motion attacks written pleadings before trial on the grounds listed above. A motion to strike at trial attacks live testimony or exhibits during the proceedings, usually right after a sustained objection, and asks the judge to remove the statement from the record and instruct the jury to disregard it.1Legal Information Institute. Motion to Strike The grounds at trial come from the rules of evidence, not Rule 12(f). A party who lets inadmissible testimony pass without objection risks waiving the chance to strike it later.
How to File a Motion to Strike
The moving party prepares a written motion that identifies exactly what should come out. Vague requests to remove “improper allegations” fail. The motion must quote or precisely reference the specific paragraphs, sentences, or defenses at issue and explain which Rule 12(f) ground applies to each.
A supporting legal brief accompanies the motion, laying out the argument for why the targeted material meets the standard for removal. Both documents are filed with the court and served on the opposing party. A motion that skips the legal argument or fails to pinpoint the offending content is almost certain to be denied.
The Deadline
In federal court, a party must file the motion before filing a responsive pleading. If no responsive pleading is allowed, the deadline is 21 days after being served with the challenged pleading.2Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Section: (f) Motion to Strike
Missing that window is not automatically fatal. Rule 12(f) does not appear in Rule 12(h)’s list of defenses permanently waived if not raised early.3Legal Information Institute. Federal Rules of Civil Procedure Rule 12 – Section: (h) Waiving and Preserving Certain Defenses Because the court retains independent authority to strike material at any time, judges sometimes entertain late motions when the content is clearly improper. Still, the further past the deadline you file, the harder the sell. File on time.
Responding to a Motion to Strike
If your pleading is the target, you must file a written opposition by the court’s deadline. The opposition has to do more than restate the original pleading. It needs to explain, with specificity, why the challenged material is relevant to the claims or defenses and why removing it would harm your ability to litigate.
When the motion attacks an affirmative defense as legally insufficient, the response must show that the defense is recognized under the applicable law and that the pleading adequately states it. Citing relevant case law is the most effective approach. A bare assertion that “the defense is valid” without supporting authority rarely persuades. Most courts schedule oral argument, so be ready to answer the judge’s questions directly, especially the central one: would keeping this material in cause actual prejudice?
How Courts Rule
After reviewing the motion, the opposition, and any argument, the judge grants or denies the request. If denied, the challenged material stays and the case moves forward unchanged.
If granted, the court orders the specified material removed. This can meaningfully narrow the case. Striking a key affirmative defense, for instance, may leave a defendant with no viable path to avoiding liability on a particular claim.
Courts often grant the motion with leave to amend, giving the affected party a set period to file a corrected pleading that cures the problems the court identified. The federal rules direct courts to “freely give leave when justice so requires.” If the party amends, the other side gets at least 14 days to respond to the amended pleading or the remainder of the original response period, whichever is longer.4Legal Information Institute. Federal Rules of Civil Procedure Rule 15 – Amended and Supplemental Pleadings
Sometimes a court grants the motion without leave to amend, usually when the defect cannot be cured. If the defense or allegation is legally invalid no matter how it is rewritten, the stricken material is gone permanently and the case proceeds without it.
Sanctions for Frivolous Motions
Filing a motion to strike that has no legitimate basis can trigger sanctions under Rule 11. The rule requires every motion to be supported by existing law, nonfrivolous legal arguments, and factual allegations with evidentiary support. A motion filed purely to harass, delay, or run up the other side’s costs violates that standard.5Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers
Rule 11 sanctions are meant to deter, not compensate. Any sanction must be “limited to what suffices to deter repetition of the conduct.” Options include nonmonetary directives, a penalty paid to the court, or an order to pay the opposing party’s reasonable attorney’s fees and expenses caused by the violation.5Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers
There is a built-in safety valve. Before filing a Rule 11 motion with the court, the opposing party must first serve it on the offending party and wait 21 days. If the frivolous motion is withdrawn or corrected during that window, the sanctions motion cannot be filed.5Legal Information Institute. Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers The court can also initiate sanctions on its own by issuing a show-cause order.
Anti-SLAPP Special Motions to Strike
More than 30 states have enacted anti-SLAPP laws, which create a special type of motion to strike aimed at lawsuits that target someone’s exercise of free speech or the right to petition the government. These “special motions to strike” operate differently from a standard Rule 12(f) motion. They shift the burden to the plaintiff to show the lawsuit has legal merit backed by admissible evidence. In some states, filing the special motion automatically pauses discovery and gives the defendant an immediate right to appeal if the motion is denied.
Fee-shifting is also different. In many states, a defendant who wins an anti-SLAPP motion can recover attorney’s fees from the plaintiff. Whether these state laws apply in federal court remains unsettled. Several federal courts have held that state anti-SLAPP procedures conflict with the Federal Rules of Civil Procedure, while others have allowed them. If your case involves speech on a public issue, the anti-SLAPP rules in your state may give you a tool beyond the standard motion to strike.