The court system of Niue is a three-tiered judicial system established by the Niue Constitution Act in the island nation of Niue. It consists of the High Court, which has original jurisdiction to hear all criminal, civil and land matters, the Court of Appeal, which has appellate civil and criminal jurisdiction, and the Privy Council in England. Justices interpret the law subject to the Constitution of Niue, and if they determine a law violates the Constitution then the Constitution takes precedence. A system of common law is used in the court system, and the Doctrine of Precedent ensures that lower courts follow the precedent of upper courts. The civil and criminal courts operate under an adversarial legal system, while the land courts operate under an inquisitive legal system.