Which one of the following terms describes the established rules and principles derived from court decisions?

The term that describes the established rules and principles derived from court decisions is case law. Case law is formed by the judgments and decisions made by judges in court cases, which set precedents for future cases. This body of law evolves through the judicial interpretation of statutes and legal principles over time, contributing to the common law that guides legal reasoning and decision-making.

Statutory law, on the other hand, is created by legislatures and consists of statutes enacted by federal, state, or local governments. While it is an essential aspect of the legal system, it is distinct from case law, which specifically stems from judicial rulings. Administrative law refers to the rules and regulations established by government agencies, and constitutional law involves the rules and principles set out in a constitution. Each of these categories plays a crucial role in the legal framework, but case law uniquely encompasses the precedents set by court decisions.