What is referred to as a decision made by a judge that becomes part of the law on the subject?

A decision made by a judge that becomes part of the law on a particular subject is known as legal precedent. This concept is crucial within the judicial system because it establishes a guideline for future cases with similar circumstances, ensuring consistency and predictability in the law.

When a judge issues a ruling or opinion, that decision can serve as a reference for other courts when faced with comparable legal issues. This process is central to common law systems, where case law plays a pivotal role in shaping legal standards. Legal precedents are developed through the interpretations and applications of existing statutes and legal principles, demonstrating the importance of judicial decisions in the evolution of law.

In contrast, a legal statute is a written law enacted by a legislative body, judicial review pertains to the power of courts to assess the constitutionality of legislative actions, and a legal ordinance is typically a regulation set by a local government or public authority. Each of these terms has its distinctive role in law, but they do not capture the specific idea of a judicial decision becoming law through precedent.