New Zealand Law

New Zealand's legal system follows the English common law tradition brought by British colonization, and rests on three foundational principles: parliamentary sovereignty, the rule of law, and the separation of powers. Its law is drawn from two main sources, legislation passed by Parliament and decisions of New Zealand's own courts, which together build the body of governing law through the common law method of precedent and stare decisis, under which lower courts follow the rulings of more senior ones. Before European colonization, Maori customary law, tikanga, governed the country, and the 1840 Treaty of Waitangi between the Crown and Maori chiefs has become an increasingly significant part of New Zealand's constitutional life, though it was not formally given legal effect until the Treaty of Waitangi Act of 1975 established the Waitangi Tribunal to investigate claims that the Crown had acted inconsistently with the treaty's principles. The New Zealand Bill of Rights Act 1990 affirms rights drawn from the International Covenant on Civil and Political Rights; it is not superior to other legislation, but courts must interpret statutes consistently with it wherever that is possible.