Case law

Case law is the set of existing rulings which made new interpretations of law and, therefore, can be cited as precedents. In some countries, such as the United States, the term is exclusively used for judicial decisions of selected appellate courts, courts of first instance, and other bodies discharging judicial functions. In other countries, such as most European countries, the term is applied to any set of rulings on law which is guided by previous rulings, for example, patent office case law. These interpretations are distinguished from statutory law which are the statutes and codes enacted by legislative bodies; regulatory law which are regulations established by governmental agencies based on statutes; and in some states, common law which are the generally accepted laws carried to the colonies and former colonies of England (USA, Australia, etc.). Trials and hearings which are not selected as 'courts of first impression' do not have rulings that become case law; therefore, these rulings cannot be precedents for future court decisions.

The legal systems of the Nordic countries are sometimes included among the civil law systems, but as a separate branch, and sometimes counted as separate from the civil law tradition. In Sweden, for instance, case law arguably plays a more important role than in some of the Continental civil law systems. The two highest courts, the Supreme Court (Högsta domstolen) and the Supreme Administrative Court (Regeringsrätten), have the right to set precedent which is in practice (however not formally) binding on all future application of the law. Courts of appeal, both general courts (hovrätter) and administrative courts (kammarrätter) may also issue decisions that act as guides for the application of the law, but these decisions may be overturned by higher courts.

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 deviate from its earlier decisions, although in practice it rarely does so.

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