A complete practitioner's treatment of constitutional tort litigation under 42 U.S.C. Section 1983, built for both plaintiff and defense. Part I sets out the statute and its two elements, including the state action tests that decide when a private party is treated as the state and the Talevski framework for enforcing federal statutes through Section 1983. Part II catalogs the substantive claims: Fourth Amendment seizures and force under Graham, conditions of confinement and medical care under the Eighth and Fourteenth Amendments, procedural and substantive due process including the DeShaney no-duty rule and the state-created danger exception, equal protection including class-of-one claims, and First Amendment retaliation after Nieves and Gonzalez v. Trevino. Part III sorts out defendants: individual versus official capacity, the Eleventh Amendment and Ex parte Young, municipal liability under Monell and its four routes, supervisory liability after Iqbal, and private contractors. Part IV covers absolute and qualified immunity and the procedural machinery that makes qualified immunity decisive. Part V covers Sections 1985 and 1986, Bivens, and the parallel statutory regimes. Part VI is procedure from limitations and accrual through the Heck bar, PLRA exhaustion, pleading, discovery, and trial. Part VII covers damages and Section 1988 fees. Part VIII covers the state law analogues that eliminate qualified immunity.