The vagueness doctrine is a Constitutional requirement criminal laws must explicitly state and define what conduct is prohibited and punishable. Under the vagueness doctrine, a criminal law cannot be too obscure for the average American citizen to understand and follow. Criminal laws that violate this requirement are then void for vagueness. The vagueness doctrine is commonly associated with overbreadth.
Vagueness doctrine rests on the due process clauses of the Fifth and Fourteenth Amendments of the U.S. Constitution. The Supreme Court stated in Winters v New York, that U.S. citizens should not have to speculate the meaning of a law due to its vagueness, the law should be clear on its face.
The vagueness doctrine protects due process because a law that is too vague does not provide adequate direction to law-abiding citizens or the justice system resulting in unfair trials. By requiring fair notice of what is punishable and what is not, vagueness doctrine also helps prevent arbitrary enforcement of the laws. Under vagueness doctrine, a statute is also void for vagueness if a legislature's delegation of authority to judges and/or administrators is so extensive that it would lead to arbitrary prosecutions.
[Last updated in July of 2024 by the Wex Definitions Team]