Criminal law vagueness

Criminal laws that violate this requirement are said to be void for vagueness .
Vagueness doctrine rests on the due process clauses of the Fifth and Fourteenth Amendments of the U.S.
Constitution.
By requiring fair notice of what is punishable and what is not, vagueness doctrine also helps prevent arbitrary enforcement of the laws.

1) In criminal law, a declaration that a law is invalid because it is not sufficiently clear.
Laws are usually found void for vagueness if, after setting some requirement or punishment, the law does not specify what is required or what conduct is punishable.
For more information, see vagueness doctrine.

The void for vagueness doctrine requires that laws are so written that they explicitly and definitely state what conduct is punishable.
The doctrine thus serves two purposes.
First, all persons receive a fair notice of what is punishable and what is not.
Second, it helps prevent arbitrary enforcement of the laws and arbitrary prosecutions.

In other situations, a statute may be unconstitutionally vague because the statute is worded in a standardless way that invites arbitrary enforcement.
In this vein, the Court has invalidated two kinds of laws as “void for vagueness”: