Summary Judgment (Rule 56) vs. Motion to Dismiss (Rule 12(b)(6))
A detailed comparison of these two civil procedure rules, including key differences, exam strategies, and guidance on when to apply each.
Overview
Summary judgment under Rule 56 and a motion to dismiss under Rule 12(b)(6) are both dispositive motions that can end a case before trial, but they arise at different stages of litigation, consider different materials, and apply different standards.
A Rule 12(b)(6) motion to dismiss tests the legal sufficiency of the plaintiff's complaint. The court examines only the complaint itself (and documents incorporated by reference or integral to the complaint) and asks whether, accepting all well-pleaded factual allegations as true and drawing all reasonable inferences in the plaintiff's favor, the complaint states a claim that is plausible on its face. Under Twombly and Iqbal, the court ignores conclusory allegations and threadbare recitals of elements. No discovery has occurred, and the court makes no factual determinations.
Summary judgment under Rule 56, by contrast, is typically filed after discovery and considers the entire evidentiary record, including depositions, interrogatory answers, documents, and affidavits. The standard is whether there is any genuine dispute of material fact such that a reasonable jury could find for the non-moving party. The court does not weigh evidence or assess credibility but views the evidence in the light most favorable to the non-moving party. If no reasonable jury could find for the non-movant, judgment is entered as a matter of law.
The timing and strategic implications differ significantly. A 12(b)(6) motion is filed early, often before any discovery costs are incurred. If successful, the case ends quickly and cheaply. Summary judgment comes later, after the parties have invested in discovery, and can dispose of claims that survive the pleading stage but lack evidentiary support.
Key Differences
| Aspect | Summary Judgment (Rule 56) | Motion to Dismiss (Rule 12(b)(6)) |
|---|---|---|
| Timing | After discovery (or at any time with evidence) | Early in litigation, before or instead of an answer |
| Materials considered | Full evidentiary record (depositions, documents, affidavits) | Only the complaint and incorporated documents |
| Standard | No genuine dispute of material fact; movant entitled to judgment as a matter of law | Complaint must state a plausible claim on its face (Twombly/Iqbal) |
| Factual assumptions | Court views evidence in light most favorable to non-movant but does not accept bare assertions | Court accepts all well-pleaded allegations as true |
| Purpose | Tests whether evidence supports the claim sufficiently for trial | Tests whether the complaint states a legally sufficient claim |
Exam Tips
On a civil procedure exam, the key distinction is what materials the court considers. A 12(b)(6) motion looks only at the complaint and tests legal sufficiency. Summary judgment looks at the evidence and tests factual sufficiency. A common exam trick is a 12(b)(6) motion that references evidence outside the pleadings: if the court considers that evidence, the motion is converted to summary judgment under Rule 12(d), and all parties must be given notice and an opportunity to present evidence. Also note that a plaintiff can survive 12(b)(6) with plausible allegations but still lose at summary judgment if they cannot support those allegations with evidence.
When to Apply Which
Apply Rule 12(b)(6) when the challenge is to the face of the complaint: the defendant argues that even if everything in the complaint is true, it does not state a viable legal claim. Apply Rule 56 when the challenge is to the evidence: the movant argues that after discovery, there is no genuine factual dispute and they are entitled to judgment as a matter of law. In practice, defendants often file a 12(b)(6) motion first, and if it fails, proceed to summary judgment after discovery.