Special legislation is a legal term of art used in the United States which refers to acts of a state legislature which apply only to part of a class—a particular person, thing, or locale within a given class. In most states, if a general law can be enacted, the legislature may not enact a special law, except a local law; and there are certain subjects on which the legislature cannot enact even local law. In some states, whether a law is “special” is determined by the courts; whether a general law could have been made applicable in is judicially determined without regard to any legislative assertion on that subject. Other states allow the legislature to determine whether a bill is special legislation.
In some states, such as Pennsylvania, the state constitution prohibits special legislation; though it is often possible for the legislature to evade this restriction by describing the community in great detail without mentioning its name. (For example, Pennsylvania law defines certain powers of "cities of the second class", which was originally defined specifically to apply only to Pittsburgh; the lower threshold of this class has been revised downward to accommodate a decline in Pittsburgh's population, with the effect that other cities not originally envisioned have become entitled to second-class status.)
At the opposite end of the spectrum, in some states—particularly the New England states—the state legislature has plenary authority over municipalities, and may create or abolish them, or change their governing laws, at will. These states typically have very weak traditions of home rule, such that any significant legal change to a city or town's charter or governing laws, or an agreement between municipalities, must be authorized by an act of the legislature. There is usually a legal process by which a community may petition the legislature for such a change, and the outcome of this process, if the legislature consents, is special legislation.
In the middle are states like Georgia, where the state legislature must charter any new city, but does not have the power to directly change a charter. The city of Sandy Springs, one of the largest in Georgia, languished unincorporated for years despite local efforts due to the politics involved in this method, which prevented the affected people from voting on their own fate. Sandy Springs was finally incorporated in December 2005. The Georgia General Assembly may also revoke a city charter, as it did en masse in 1995 from every city which did not offer at least three distinct services to its citizens.
The term "special legislation" may also apply in some states to legislation which names a particular person, as in appointment to a government position or conveyance of real property between an individual and the state, or between an individual and an unincorporated community.