355 U.S. 41 (1957) (U.S. Supreme Court)
Conley v. Gibson is the classic statement of the Federal Rules' original, liberal notice-pleading philosophy.
Under Federal Rule of Civil Procedure 8(a), must a plaintiff plead detailed, specific facts to survive a Rule 12(b)(6) motion, or does a short and plain statement giving fair notice of the claim and its grounds suffice?
Rule 8(a)(2) requires only a short and plain statement of the claim showing that the pleader is entitled to relief, sufficient to give the defendant fair notice of what the claim is and the grounds upon which it rests. A complaint should not be dismissed for failure to state a claim unless it appears beyond doubt that the plaintiff can prove no set of facts in support of the claim that would entitle the plaintiff to relief. If greater particularity is desired, the proper recourse is a motion for a more definite statement under Rule 12(e) or use of discovery, not dismissal.
The complaint satisfied Rule 8(a)'s notice-pleading standard and should not have been dismissed. The Supreme Court reversed the judgment and remanded.
Conley entrenched the ethos of Rule 8(a)'s notice pleading and shaped Rule 12(b)(6) practice for decades. Its low dismissal threshold—survival unless there is no set of facts consistent with the allegations that could entitle relief—minimized front-loaded factual detail and channeled disputes into discovery. Although Twombly and Iqbal later replaced the "no set of facts" formulation with a plausibility standard that requires more factual content, Conley remains vital for understanding the purpose of pleadings (fair notice), the availability of Rule 12(e) and discovery to obtain detail, and the historical baseline against which modern pleading debates are measured.