For well over a decade, the cannabis industry has grown exponentially in scope and revenue. Industry participants range from giant food and beverage companies to e-commerce platforms, dispensaries, pet food companies, and growers. These companies are developing and marketing products that involve cannabis in all forms and derivatives, including THC, CBD, and hemp products, as well as other emerging cannabinoid products such as CBG. And as the industry has grown and diversified, so too has its legal needs. Today, in addition to longstanding questions of federal legality and tension with state law, cannabis companies face a broad range of issues that require sophisticated legal guidance. For example, legal questions may involve anything from litigation and real estate to advertising and food and drug law. These questions are especially challenging given the breakneck pace with which cannabis policy and law has developed within a patchwork of federal, state, and local systems. Failure to navigate these concerns deftly and thoughtfully jeopardizes financial growth, not to mention business survival. Until now, there has been no single reference to guide cannabis lawyers along the full continuum of potential legal needs challenging the industry. This treatise fills that gap from a sophisticated perspective by flagging key issues in more than a dozen practice areas and covering the impact of cannabis policy from federal and Canadian enforcement and regulatory agencies. By mapping these diverse concerns, this treatise helps provide useful guardrails for in-house and outside counsel alike.