Also known as:vagueness doctrine · void-for-vagueness doctrine · void for vagueness · void-for-vagueness
Written by attorneys · grounded in primary & secondary sources — see below
A constitutional doctrine under the Due Process Clause that invalidates a law when its terms are so indefinite that ordinary people cannot understand what conduct is prohibited or when the law fails to supply clear standards that constrain arbitrary or discriminatory enforcement.
Sources & Authorities
How it applies
Common Examples
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Attorney Press Statement Sanction
Victoria Vernon, a defense lawyer, held a press conference describing the prosecution's key witness as motivated by a plea deal. The state bar charged her under a publicity rule that barred statements creating a substantial likelihood of prejudice yet allowed statements about the general nature of the defense without elaboration. Because the safe-harbor language gave no objective line between permitted description and prohibited detail, the disciplinary board could not determine whether Vernon's remarks fell inside or outside the prohibition.
Gang Loitering Dispersal Order
Vera Vu stood on a Chicago sidewalk with two acquaintances for twenty minutes. An officer ordered the group to disperse under an ordinance that made it unlawful for any person to remain in one place with no apparent purpose when a known gang member was present. Because the ordinance supplied no objective criteria for determining when presence became loitering, the officer's order rested on an unguided assessment of apparent purpose.
Select any source to read its text and confirm it supports the definition.
Cases
Study Supplements
City of Chicago v. Morales527 U.S. 41, 119 S.Ct. 1849, 144 L.Ed.2d 67 (1999)
Injunction Contempt Citation
Vincent Vale led a march that city officials claimed violated an injunction barring parades without a permit. The injunction used the phrase conduct that tends to disturb the public peace. When officials sought contempt sanctions, Vale argued the injunction's language left participants unable to know in advance what conduct would trigger liability.
Walker v. City of Birmingham388 U.S. 307 (1967)
Solicitation Rule Challenge
Valerie Voss, an NAACP organizer, advised local residents about possible litigation against school segregation. State bar officials charged her with improper solicitation under a rule that prohibited any conduct that might lead to litigation. Because the rule supplied no concrete line between protected advice and forbidden encouragement, Voss could not determine what speech remained lawful.
N.A.A.C.P. v. Button371 U.S. 415, 83 S. Ct. 328, 9 L. Ed. 2d 405 (1963)
Housing Complex Trespass Notice
Violet Vidal entered a public housing complex to visit a resident friend. Police issued a trespass notice under a policy that barred entry by anyone without a legitimate purpose. Because the policy left officers free to decide what counted as a legitimate purpose, Vidal could not know whether her visit would later be deemed unlawful.
Virginia v. Hicks539 U.S. 113
Loitering Identification Demand
Valerie Viera walked along a public street after dark. An officer stopped her under a statute requiring loiterers to provide credible and reliable identification. Because the statute gave no definition of credible and reliable, Viera could not know what form of identification would satisfy the demand or protect her from arrest.
Kolender v. Lawson461 U.S. 352, 103 S.Ct. 1855, 75 L.Ed.2d 903 (1983)
Common questions
Frequently Asked
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What two core requirements must a law satisfy to avoid a vagueness challenge?+
A law must give ordinary people fair notice of what conduct is prohibited and must supply explicit standards that constrain arbitrary or discriminatory enforcement by officials.
Supporting sources
Why does an ordinance using the phrase no apparent shopping intent fail vagueness review?+
The phrase turns entirely on an officer's subjective assessment of unseen motives rather than on observable conduct, leaving ordinary people unable to predict when presence becomes unlawful and giving officers unguided discretion to target disfavored groups.
Supporting sources
Does training officers to look for observable indicators such as sitting without shopping bags cure vagueness in a loitering ordinance?+
No. Observable indicators remain mere proxies for an officer's subjective judgment about an unseen mental state, so they do not supply the definite standards required by due process.
Supporting sources
When is a rule regulating attorney speech to the press unconstitutionally vague?+
A rule is unconstitutionally vague when it prohibits statements creating a substantial likelihood of prejudice yet simultaneously authorizes statements about the general nature of the defense without clear boundaries between the two categories.
Supporting sources
401 U.S. 37 (1971)Constitutional Law
…jurisdiction and power to restrain the District Attorney from prosecuting, held that the State's Criminal Syndicalism Act was void for vagueness and overbreadth in violation of the First and Fourteenth Amendments, and accordingly restrained the District Attorney from "further prosecution of the currently pending action against…