This guide covers cannabis and controlled substances law from the federal statutory framework through state programs, business compliance, and record relief. It begins with the Controlled Substances Act, the scheduling structure, and the reasons state legalization does not displace federal prohibition. A full part inventories the federal consequences state law cannot cure — firearms, immigration, federal employment and housing, taxation under section 280E, banking, bankruptcy, and intellectual property. Separate parts address state medical and adult-use program design, licensing and operational compliance, employment testing and accommodation across divergent state rules, and hemp-derived products. Further parts cover prescribing and practitioner liability, defending a controlled substance charge including search, possession, intent, quantity, and forfeiture, and the record relief mechanisms now available in many states. The guide closes with driving, family and housing consequences, worked problems, and a reference section. Authority is cited and linked throughout.