query: How many countries in the world use common law?
passage: 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.
passage: Commonwealth of Nations
Due to their shared constitutional histories, several countries in the Commonwealth have similar legal and political systems. The Commonwealth requires its members to be functioning democracies that respect human rights and the rule of law. Most Commonwealth countries have the bicameral Westminster system of parliamentary democracy. The Commonwealth Parliamentary Association facilitates co-operation between legislatures across the Commonwealth, and the Commonwealth Local Government Forum promotes good governance amongst local government officials. Most Commonwealth members use common law, modelled on English law. The Judicial Committee of the Privy Council is the supreme court of 14 Commonwealth members.[161]