Although Britain is a unitary state, England and Wales, Scotland and Northern Ireland all have their own legal systems, with considerable differences in law, organisation and practice. However, a large amount of modern legislation applies throughout Britain. The law is divided into criminal law and civil law; the latter regulates the conduct of people in ordinary relations with one another. The distinction between the two branches of the law is reflected in the procedures used, the courts in which cases may be heard and the sanctions which may be applied.
The legal system of England and Wales comprises both an historic body of conventions known as common law and equity, and parliamentary and European Community legislation; the last of these applies throughout Britain. Common law, which is based on custom and interpreted in court cases by judges, has never been precisely defined or codified. It forms the basis of the law except when superseded by legislation. Equity law consists of a body of historic rules and principles which are applied by the courts. The English legal system is therefbre distinct from many of those of Western Europe, which have codes derived from Roman law.