Multi-level marketing occupies a genuinely contested legal space: the structure is lawful, an unlawful version of it is nearly identical from the outside, and the line between them is drawn by a doctrinal test most participants have never heard of. This article explains that test — whether compensation is paid for recruitment rather than for sales to people outside the network — and the inventory loading and buyback rules built around it. It explains the earnings claim problem, which is the source of most enforcement, and what an income disclosure statement actually shows when you read it correctly. It covers the federal business opportunity disclosure rule that reaches many programs whose operators do not know it applies to them, the franchise rule that reaches others, and the State statutes that add registration and rescission rights. It covers participant classification, tax treatment, the endorsement rules that reach every social media post, and the securities and racketeering theories that appear in private litigation. It closes with how a participant evaluates an opportunity, and how a compliant program is actually built.