The United Kingdom does not have a single body of law applicable throughout the realm. Scotland has its own distinctive system and courts; in Northern Ireland, certain spheres of law differ in substance from those operating in England and Wales. A feature common to all UK legal systems, however—and one that distinguishes them from many continental systems—is the absence of a complete code, since legislation and unwritten or common law are all part of the "constitution."
The main civil courts in England and Wales are 218 county courts for small cases and the High Court, which is divided into the chancery division, the family division, and the Queen's Bench division (including the maritime and commercial courts), for the more important cases. Appeals from the county courts may also be heard in the High Court, though the more important ones come before the Court of Appeal; a few appeals are heard before the House of Lords, which is the ultimate court of appeal for civil cases throughout the United Kingdom. In Scotland, civil cases are heard at the sheriff courts (corresponding roughly to the English county courts) and in the Outer House of the Court of Session, which is the supreme civil court in Scotland; appeals are heard by the Inner House of the Court of Session. Trial by jury in civil cases is common in Scotland but rare in the rest of the United Kingdom.
Criminal courts in England and Wales include magistrates' courts, which try less serious offenses (some 96% of all criminal cases) and consist most often of three unpaid magistrates known as justices of the peace, and 78 centers of the Crown Court, presided over by a bench of justices or, in the most serious cases, by a High Court judge sitting alone. All contested cases receive a jury trial. Cases involving persons under 17 years of age are heard by justices of the peace in specially constituted juvenile courts. Appeals may be heard successively by the Crown Court, the High Court, the Court of Criminal Appeal, and in certain cases by the House of Lords. In Scotland, minor criminal cases are tried without jury in the sheriff courts and district courts, and more serious cases with a jury in the sheriff courts. The supreme criminal court is the High Court of Justiciary, where cases are heard by a judge sitting with a jury; this is also the ultimate appeals court.
All criminal trials are held in open court. In England, Wales, and Northern Ireland, 12-citizen juries must unanimously decide the verdict unless, with no more than two jurors dissenting, the judge directs them to return a majority verdict. Scottish juries of 15 persons are permitted to reach a majority decision and, if warranted, a verdict of "not proven." Among temporary emergency measures passed with the aim of controlling terrorism in Northern Ireland are those empowering ministers to order the search, arrest, and detention of suspected terrorists and permitting juryless trials for terrorist acts in Northern Ireland.
Central responsibility for the administration of the judicial system lies with the lord chancellor (who heads the judiciary and also serves as a cabinet minister and as speaker of the House of Lords) and the home secretary (and the secretaries of state for Scotland and for Northern Ireland). Judges are appointed by the crown, on the advice of the prime minister, lord chancellor, or the appropriate cabinet ministries.
The United Kingdom accepts the compulsory jurisdiction of the International Court of Justice with reservations.