Zoning is the most consequential body of law most Americans never read, and it is written not in the United States Code but in a state enabling act and a municipal ordinance nobody outside city hall has opened in years. This UpLaw guide maps the whole field: the police-power foundation the Supreme Court blessed in Village of Euclid v. Ambler Realty, the anatomy of a zoning ordinance and map, permitted and conditional uses, dimensional and bulk standards, nonconforming uses and vested rights, and the relief mechanisms — variances, special use permits, rezonings, and planned unit developments — that make a rigid code workable. It explains the legislative/quasi-judicial distinction that silently controls the standard of review, the doctrines of spot zoning and contract zoning, and how subdivision regulation, dedications, and impact fees actually get imposed. It then works through regulatory takings in depth: Penn Central's ad hoc factors, Lucas's total-wipeout rule, and the Nollan/Dolan nexus-and-proportionality test as extended by Koontz to monetary demands and by Sheetz v. County of El Dorado to legislatively imposed conditions, along with the ripeness landscape after Knick v. Township of Scott. Due process, equal protection, the Fair Housing Act, RLUIPA, and environmental review round out the constraints, and a running hypothetical follows a developer, Alder Ridge Partners, from a wrong-zoned parcel through hearings, conditions, and court. Land use is state and local law: the framework is national, but the rules that decide your case are in your own state's cases and your own city's code.