A plaintiff starts a civil action by filing a pleading called a complaint. A complaint must state all of the plaintiff's claims against the defendant, and must also specify what remedy the plaintiff wants. After receiving the complaint, the defendant must respond with an answer.
Traditionally, in accord with federal courts' system of notice pleading, complaints (like other pleadings) did not need to be very specific, and did not need to specify the facts the plaintiff intends to prove. The Supreme Court introduced a heightened standard for complaints in 2007 with the case Bell Atlantic v. Twombly. This case requires that a complaint must allege "enough facts to state a claim to relief that is plausible on its face."
Although some state courts model their pleading rules on the Federal Rules of Civil Procedure, other states use very different rules. Thus, pleading standards for complaints may vary widely from state to state, or between state and federal courts located in the same state. See State Civil Procedure Rules.
The Supreme Court recently reiterated the level of detail required in a complaint in the case of Ashcroft v. Iqbal.
See also Wex: Civil Procedure;