This guide treats owner liability as a family of separate doctrines rather than a single claim, because the theory a practitioner selects determines the elements, the evidence, and usually the outcome. It sets out the alter ego test as courts actually apply it, ranks the factors by the weight they carry, and explains why bank records decide most cases. It then works through the routes that reach an owner without disregarding the entity at all: direct participation, statutory operator and responsible person liability, securities control person claims, racketeering claims that depend on separateness rather than defeating it, fraudulent transfer, and successor liability. Bankruptcy remedies receive separate treatment, including equitable subordination and substantive consolidation. The guide closes with a governance program ranked by effect, a discovery plan for creditors, and a defense sequence.