Most modern law is contained in statutes and administrative regulations, which lawyers tend to confront alongside case law in almost every area of practice. Building on basic concepts of Legislation and Regulation, this course explores theories of the legislative process, judicial power, and agency deference—all in the interpretation and implementation of legislation. We will explore the history of and ongoing controversies about legislation, regulation, and interpretation, including deep debates about textualism and purposive or dynamic interpretation; about the increasingly popular use of canons of construction; and about the constitutional foundations and ends of statutory interpretation. We will take close stock of the nature and trajectory of scholarly debates, paying close attention to the empirical work and data science approaches to ongoing debates in the field. Throughout, we will focus on major statutory interpretation cases at the Supreme Court. Although there is no single subject matter focus of the course, a significant portion of the substantive areas of law we traverse will cover criminal law and anti-discrimination law.