<P> Case law is a set of past rulings by tribunals that meet their respective jurisdictions' rules to be cited as precedent . These interpretations are distinguished from statutory law, which are the statutes and codes enacted by legislative bodies, and regulatory law, which are regulations established by executive agencies based on statutes . The term "case law" is applied to any set of previous rulings by an adjudicatory tribunal that guides future rulings; for example, patent office case law . </P> <P> In common law countries the term is used for judicial decisions of selected appellate courts, courts of first instance, agency tribunals, and other bodies discharging adjudicatory functions . In common law countries, "case law" is a near - exact synonym for "common law". </P> <P> In the common law tradition, courts decide the law applicable to a case by interpreting statutes and applying precedents which record how and why prior cases have been decided . Unlike most civil law systems, common law systems follow the doctrine of stare decisis, by which most courts are bound by their own previous decisions in similar cases, and all lower courts should make decisions consistent with previous decisions of higher courts . For example, in England, the High Court and the Court of Appeal are each bound by their own previous decisions, but the Supreme Court of the United Kingdom is able to deviate from its earlier decisions, although in practice it rarely does so . </P>

Discuss case law as a source of law