What does "case law" derive its authority from?

Case law derives its authority primarily from prior court rulings. This branch of law is established through judicial decisions made in courts. When judges interpret statutes or apply legal principles to specific cases, these decisions set precedents that guide future courts in similar situations. This practice of using past rulings to inform current cases is foundational to the legal system, especially in common law jurisdictions, where precedent is critical in ensuring consistency and stability in legal interpretations.

The reliance on prior court rulings allows for a body of law that evolves over time, as new cases are decided and existing precedents are either upheld or overturned. Therefore, the authority of case law is rooted in the judicial history as articulated by the courts themselves, which is why the answer emphasizing prior court rulings is indeed correct.