Federal Rule of Civil Procedure 12(b)(6) lets a defendant move to dismiss a complaint for "failure to state a claim upon which relief can be granted." The post-Twombly/Iqbal standard means motions to dismiss are now a real procedural lever, not a rubber-stamp denial.

The standard you must cite

From Bell Atlantic Corp. v. Twombly, 550 U.S. 544 (2007), and Ashcroft v. Iqbal, 556 U.S. 662 (2009) — the Twombly/Iqbal pleading standard:

Accept all well-pleaded factual allegations as true.
Conclusory legal allegations are not entitled to the assumption of truth.
The complaint must state a claim that is "plausible on its face."
"Plausibility" requires more than a sheer possibility that the defendant acted unlawfully.

Structure of the motion

1. Introduction (1 page)

State the relief you seek and the central deficiency. The first paragraph should make a judge with a stack of 40 motions understand exactly what you're asking and why in 60 seconds.

2. Factual background (2-3 pages)

Recite the plaintiff's allegations as they appear in the complaint. You can characterize them sparingly ("Plaintiff alleges, conclusorily, that…") but do not argue here.

3. Legal standard (½ page)

The standard above with citations. Keep it tight — every judge has read Twombly and Iqbal a hundred times.

4. Argument (5-8 pages)

For each claim, walk through the elements and identify what's missing. Lead with the strongest deficiency. Use headings that telegraph the win:

I. The complaint does not allege scienter, an essential element of common-law fraud.

5. Conclusion (¼ page)

Specific relief requested. Dismissal with prejudice if the defect is incurable; without prejudice if amendment could fix it — be honest with the court.

Citation strategy

Cite Supreme Court before Circuit before District.
Cite published before unpublished.
Use id. ruthlessly when the same case supports the next proposition.
Pin-cite every quote and every proposition tied to a specific page.
Validate every citation before filing — sanctions for hallucinated AI cites are real.

Common mistakes

Arguing facts outside the complaint. A 12(b)(6) is decided on the complaint's allegations + judicially noticeable documents only.
Ignoring 9(b) for fraud claims. Fraud must be pled with particularity. Argue both 9(b) and 12(b)(6) if applicable.
Forgetting Rule 11. A frivolous motion to dismiss can draw sanctions.
Burying the lede. Lead with your strongest theory; don't make the judge dig for it.

How Draftiro helps

Upload the complaint. Ask: "Draft a 12(b)(6) motion to dismiss this complaint. Identify each claim's elements and the missing allegation for each." You get a structured first draft with element-by-element analysis. Every citation is validated against CourtListener; statutes and rules are flagged as unchecked. You revise, validate, and file.

Related reading: the 12(b)(6) motion and FRCP Rule 12 glossary entries, why AI hallucinates citations and how validation catches them, and the criminal-defense workspace for suppression-motion drafting.