amicus brief

An amicus brief, from the Latin amicus curiae, meaning “friend of the court,” is a document filed by a person or organization that is not a party to a case but seeks to influence the outcome by offering the court additional facts, expertise, or legal arguments. Such briefs may generally be filed only with the consent of the parties or by leave of the court, which remains free to give them as much or as little weight as it chooses. They are most common in appellate courts and at the Supreme Court, particularly in cases of broad public or constitutional significance, where governments, scholars, advocacy organizations, and industry groups frequently submit competing briefs to shape how a ruling is reasoned and how broadly it applies.