Pleading is usually the first step in a lawsuit.^[1] This is when parties formally submit their claims and defenses. A complaint is the first pleading filed by a plaintiff which starts the lawsuit. A complaint lists the relevant allegations of fact which leads to one or more legal causes of action. It also has a prayer for relief and sometimes a statement of damages claimed. This is called an ad quod damnum clause. In some situations, a complaint is called a petition. In this case the party filing a complaint is called the petitioner and the other party is the respondent. In equity, sometimes called chancery, the initial pleading may be called either a petition or a bill of complaint in chancery.

Other terms

• When used in civil proceedings in England and Wales, the term "complaint" refers to how civil proceedings are started in the magistrates' court.^[2] The complaint may be either written or oral.

• A demurrer is a pleading (usually filed by a defendant). It objects to the legal sufficiency of the opponent's pleading and demands that the court rule immediately about whether the pleading is legally adequate. This is before the party must plead on the merits in response. Since demurrer procedure required an immediate ruling like a motion, many common law jurisdictions therefore went to a narrower understanding of pleadings. They are seen as framing the issues in a case but not being motions in and of themselves. The demurrer is replaced with the motion to dismiss for failure to state a cause of action or the application to strike out particulars of claim.

• An answer is a pleading filed by a defendant. It admits or denies the specific allegations listed in a complaint. It also serves as a general appearance by a defendant. In England and Wales, the equivalent pleading is called a defence.^[3]

• A defendant may also file a cross-complaint or third-party complaint. This is to bring other parties into a case by the process of impleader.

• A defendant may file a counter-claim. This raises a cause of action to defend, reduce or set off the claim of the plaintiff.