Does Federal Rule of Civil Procedure 11 apply to AI-generated content in a brief?

Yes. Rule 11 requires an attorney signing a filing to certify, after reasonable inquiry, that legal contentions are warranted and factual contentions have evidentiary support — a certification that applies regardless of what tool was used to draft the underlying text.

Is 'the AI told me the case was real' a valid defense under Rule 11?

No court in the sanctions record has accepted this as a defense. Judge Castel's Mata opinion held that existing rules impose a gatekeeping role on attorneys regardless of drafting tool, and the Second Circuit in Park v. Kim held that FRAP 46(c)'s equivalent duty requires attorneys to actually read the authorities they cite.

Does Rule 11 only apply to licensed attorneys?

Rule 11's text applies to attorneys and unrepresented parties who sign a filing. Kruse v. Karlen (Missouri Court of Appeals, 2024) applied the equivalent state-court verification duty to a pro se litigant and awarded $10,000 in damages for a frivolous appeal built on fabricated citations.

Does Rule 11 apply to AI-generated briefs?

https://citationsafe.com/faq/rule-11-and-ai-generated-briefs

Yes — Federal Rule of Civil Procedure 11 applies to AI-generated briefs exactly as it applies to any other filing. Rule 11(b) requires the attorney or unrepresented party signing a paper to certify, to the best of their knowledge after an inquiry reasonable under the circumstances, that legal contentions are warranted by existing law and factual contentions have evidentiary support. Nothing in the rule’s text carves out an exception for content drafted with the help of an AI tool, and no court in the public sanctions record has read one in.

What courts have actually held

Mata v. Avianca, Inc
S.D. New York — decided 2023-06-22 — 5000 USD
Monetary Fine (Lawyers & Firm); Letters to Client/Judges
Park v. Kim
2nd. Cir. CA — decided 2024-01-30
Referral to Grievance Panel + Order to Disclose Misconduct to Client.

In Mata, Judge Castel wrote that “[e]xisting rules impose a gatekeeping role on attorneys to ensure the accuracy of their filings” and found the attorneys had abandoned that responsibility by submitting fabricated opinions generated by ChatGPT — a Rule 11 analysis, not a novel AI-specific standard. In Park v. Kim, the Second Circuit’s Grievance Panel wrote that Federal Rule of Appellate Procedure 46(c) “require[s] that attorneys read, and thereby confirm the existence and validity of, the legal authorities on which they rely” — the appellate analog to Rule 11’s certification requirement, applied the same way regardless of drafting tool.

The verification duty attaches to the human, not the tool

The consistent thread across the sanctions record is that Rule 11’s “reasonable inquiry” standard is judged against what a reasonably careful attorney would have done to confirm the filing was accurate — and courts have uniformly found that accepting an AI tool’s own confident assurance is not a reasonable inquiry. Kruse v. Karlen extends this beyond licensed attorneys: the Missouri Court of Appeals applied the same verification expectation to a pro se litigant, holding that filing a brief with 22 fabricated citations, admittedly AI-generated, undermined the court’s ability to trust every filing regardless of the filer’s license status.

What “reasonable inquiry” means in practice

None of the cases in the sanctions record hold that AI-assisted drafting is itself sanctionable — the sanction follows from filing without verification, not from using the tool. See how to verify a legal citation manually for the specific steps that satisfy a reasonable-inquiry standard, and do bar rules require AI disclosure for the separate (and more jurisdiction-dependent) question of what you owe your client or the court by way of disclosure, as opposed to verification.

This page describes published court opinions and rule text for informational purposes; it is not legal advice. Rule 11’s text and interpretation can be checked directly at law.cornell.edu/rules/frcp/rule_11.

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Written by the Citation Safe Research Desk · Reviewed by Andy Gaber, Founder