COMMON LAW

the system of jurisprudence, which originated in England and was later applied in the United States, that is based on judicial precedent (court decisions or case law) rather than legislative enactment (statutes) and is therefore derived from principles rather than rules.
In the absence of statutory law regarding a particular subject, the judge-made rules of common law are the law on that subject. Thus the traditional phrase "at common law" refers to the state of the law in a particular field prior to the enactment of legislation in that field. Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016