In a civil action, the complaint is the document that initiates a lawsuit. The complaint outlines the alleged facts of the case and the basis for which a legal remedy is sought. In a criminal action, a complaint is the preliminary charge filed by the complaining party, usually with the police or a court. Civil complaints seek to remedy a harm to the plaintiff, usually with money damages, while criminal actions seek to punish and deter defendants based upon their wrongful intent. The party filing the complaint is usually called the plaintiff and the party against whom the complaint is filed is called the defendant or defendants. Complaints are pleadings and must be drafted carefully to properly state the factual as well as legal basis for the claim, although some states have approved complaint forms which can be filled in by an individual.
A complaint also must follow statutory requirements as to the form of the document. A specific type of paper may be required, and it must include certain elements. A complaint must include a caption, which names the parties involved in the action, the title of the pleading, and will contain a case number once filed. The complaint also contains the allegations forming the basis for the action and a statement of the relief requested, called the "prayer". A copy of the complaint and the summons must be served on a defendant before a response is required. A complaint filing must be accompanied by a filing fee payable to the court clerk, unless a waiver based on poverty is obtained.