Hornbook law (often used synonymously with blackletter law) refers to legal principles or concepts that have been long-established and accepted as part of the law. These concepts in common law have been repeatedly affirmed in cases often for hundreds of years, and therefore, they are very difficult to change. Hornbook law as a term originates from the hornbooks used as overviews of an area of law primarily for law students in their studies. The concepts that work their way into a hornbook are regarded as fundamental to teach new students. Since students to varying extent over the years have studied from the same hornbooks, the concepts are further ingrained into the law because students carry these concepts into their careers.
[Last updated in March of 2022 by the Wex Definitions Team]