A writ of mandamus is a court order commanding a government official, lower court, or government body to perform a duty that is purely ministerial — one that the law requires them to perform and that they have refused or failed to carry out. It is an extraordinary remedy, not a routine one, and courts grant it sparingly. What It Is Mandamus sits in the category of extraordinary writs — legal tools that exist outside the normal appellate process and are available only when ordinary remedies are inadequate.