What is case law primarily established by?

Case law is primarily established by legal precedents set by court decisions. This means that when courts make rulings on specific cases, these decisions create a body of law that can be referenced in future cases with similar circumstances. This principle is known as stare decisis, which encourages consistency and predictability in the law by allowing lower courts to refer to the principles established in higher courts' rulings.

Legal precedents provide guidance on how the law should be applied, helping to interpret statutes and fill in gaps where statutory law may be ambiguous or lacking. As new cases emerge, they add to the evolving landscape of case law, which can influence not only the outcomes of future cases but also the interpretation and application of statutory laws.

In contrast, statutes passed by legislatures represent another source of law but are not the foundation of case law. International treaties and agreements, as well as administrative agency regulations, serve different functions within the legal framework and do not establish case law in the same way that court decisions do.