Also known as:vagueness doctrine · void-for-vagueness · void for vagueness · void for vagueness doctrine
Written by attorneys · grounded in primary & secondary sources — see below
A constitutional principle that invalidates statutes or rules failing to give ordinary people fair notice of prohibited conduct or failing to supply clear standards that constrain official discretion. The doctrine protects against arbitrary enforcement and chills on lawful activity by requiring explicit guidelines rather than subjective or indeterminate terms.
Sources & Authorities
How it applies
Common Examples
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Attorney Press Statements Challenged
Dustin Donovan, a defense lawyer, held a press conference describing evidence that he believed exonerated his client. The state bar later charged him under a rule barring statements creating a substantial likelihood of prejudicing a proceeding while allowing only vague elaboration on the general nature of the defense. The disciplinary board could not determine whether Donovan's comments crossed the line, leaving him without fair notice of what speech was safe.
Gang Loitering Dispersal Order
Deborah Dunn stood on a Chicago sidewalk talking with two acquaintances for twenty minutes. An officer ordered her to move along under an ordinance that prohibited remaining in one place with no apparent purpose when a known gang member was present. Dunn could not predict whether her conversation would be viewed as loitering, and the officer exercised unchecked discretion in deciding whom to disperse.
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Cases
Casebooks
City of Chicago v. Morales527 U.S. 41, 119 S.Ct. 1849, 144 L.Ed.2d 67 (1999)
Parade Permit Injunction Dispute
Doris Duffy organized a protest march without first obtaining a permit required by a city ordinance that banned parades causing traffic disruption or public inconvenience. Police arrested her for violating an injunction enforcing the ordinance. The ordinance's broad terms left organizers unable to know in advance what level of disruption would trigger enforcement.
Walker v. City of Birmingham388 U.S. 307 (1967)
Child Pornography Possession Charge
David Dawson possessed photographs that a statute prohibited if they showed a minor in a state of nudity for purposes of sexual stimulation. The law contained no definition of the prohibited purpose or visual threshold. Dawson could not determine whether his materials fell within the statute's reach before facing prosecution.
Osborne v. Ohio495 U.S. 103 (1990)
Housing Project Trespass Arrest
Dolores Diaz entered a public housing complex to visit a friend and was arrested under a rule barring nonresidents from the property without a specific invitation. The rule supplied no guidance on how officers should verify invitations or distinguish legitimate visitors from trespassers. Diaz had no way to know whether her presence would be deemed unauthorized.
Virginia v. Hicks539 U.S. 113
Sex Offender Registration Requirement
Destiny Davis was convicted of a federal offense and ordered to register as a sex offender under a statute delegating to the Attorney General the power to decide which pre-enactment offenders must comply. The statute provided no explicit standard for the Attorney General's decision. Davis could not ascertain whether registration applied to her until after the Attorney General acted.
Gundy v. United States139 S. Ct. 2116 (2019)
Common questions
Frequently Asked
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What two core requirements must a law satisfy to avoid a vagueness challenge under due process?+
A law must give ordinary people fair notice of what conduct is prohibited and must supply clear standards that constrain official discretion. Failure on either prong renders the law unconstitutionally vague.
Why does an ordinance using the phrase no apparent shopping intent invite arbitrary enforcement?+
The phrase turns on an officer's subjective assessment of unseen motives rather than observable conduct. Different officers can reach opposite conclusions about the same behavior, leaving enforcement to unguided discretion.
Does training officers on observable indicators cure vagueness in an anti-loitering ordinance?+
No. Observable proxies such as sitting without shopping bags still require officers to infer an unseen mental state of no apparent purpose. The training therefore leaves the same subjective judgment intact.
When does a rule regulating speech become vulnerable to a vagueness claim even if it has some legitimate applications?+
A rule becomes vulnerable when its key terms are so indeterminate that speakers cannot predict what is forbidden and officials can selectively enforce against disfavored expression. The presence of legitimate applications does not cure the lack of fair notice or the risk of arbitrary enforcement.
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…