This guide covers False Claims Act practice from evaluating a potential case through resolution and the relator's share. It begins with the liability provisions, the expansive definition of knowledge, and the demanding materiality standard that now governs implied certification theories. A full part addresses the procedural architecture that makes qui tam practice unique: filing under seal, the disclosure statement, civil investigative demands, seal extensions, and the intervention decision. Separate parts cover the bars that eliminate otherwise strong cases, the pleading standard, limitations, and standing. Further parts address the substantive theories in health care and government contracting, including anti-kickback and self-referral linkage; damages, penalties, and the relator share framework; retaliation claims and their independent remedies; and defense strategy including materiality attacks, government dismissal, and collateral consequences. The guide closes with practical relator counseling, worked problems, and a reference section. Authority is cited and linked throughout.