List of national legal systems
Common law is currently in practice in Ireland, most of the United Kingdom (England and Wales and Northern Ireland), Australia, New Zealand, Bangladesh, India (excluding Goa), Pakistan, South Africa, Canada (excluding Quebec), Hong Kong, the United States (on a state level excluding Louisiana), and many other places. In addition to these countries, several others have adapted the common law system into a mixed system. For example, Nigeria operates largely on a common law system, but incorporates religious law.
International law
The term "international law" is sometimes divided into "public" and "private" international law, particularly by civil law scholars, who seek to follow a Roman tradition. Roman lawyers would have further distinguished "jus gentium", the law of nations, and "jus inter gentes" – agreements between nations. On this view, "public" international law is said to cover relations between nation-states, and includes fields such as treaty law, law of sea, international criminal law, the laws of war or international humanitarian law, international human rights law, and refugee law. By contrast "private" international law, which is more commonly termed "conflict of laws", concerns whether courts within countries claim jurisdiction over cases with a foreign element, and which country's law applies. A further concept, more recently developing, is of "supranational law", on the law of supranational organizations. This concerns regional agreements where the laws of nation states may be held inapplicable when conflicting with a supranational legal system when that nation has a treaty obligation to a supranational collective. Systems of "supranational law" arise when nations explicitly cede their right to make certain judicial decisions to a common tribunal. The decisions of the common tribunal are directly effective in each party nation, and have priority over decisions taken by national courts. The European Union is an example of an international treaty organization which implements a supranational legal framework, with the European Court of Justice having supremacy over all member-nation courts in matter of European Union law. A further frequently used term is "transnational law", which refers to a body of rules that transcend the nation state.