Common Law

The common law is the body of legal rules created over time by judges as they issue written opinions resolving individual lawsuits. The opinions serve as precedents to guide the resolution of future similar cases. The common law is to be contrasted with positive law, which consists of statutes passed by legislatures.

The principal subject areas of the common law are contracts, property, and torts. Common law originated as customary rules of social conduct that came to be enforced in the English courts. It also applied in the British colonies and was adopted by the fledgling United States, whose courts adapted it as necessary to suit the American experience.

The common law has three distinctive features that define it and set it apart from positive law. First, it is not a written code. There is no single source, such as a statute book, that codifies the principles that apply to a given case.

Second, common law develops through the resolution of actual legal controversies, primarily at the appellate level. The judge's opinion typically sets forth the facts and the applicable legal principles and resolves the case by applying the principles to the facts.

Third, the common law develops through the accumulation of these opinions, or precedents, as they are applied to similar cases in the future. The doctrine of precedent is based on the principle of stare decisis (to stand by a decision), which binds courts to follow prior judicial decisions unless circumstances (e.g., a change in societal norms) compel a reexamination or overturning of a prior case. The doctrine is intended to ensure that the same legal principles apply to all similarly situated parties. It also establishes the rule of law: Basing decisions on precedent ensures that society is governed by established rules rather than the personal views of each judge.