Legal term referring to the body of law derived from judicial decisions and custom, as opposed to statutory law. Used in contexts comparing legal systems.
In the UK and the US, common law plays an important role.
慣習法 is customary law (unwritten rules based on long-standing practice), whereas 普通法 is a formal legal system developed through court decisions.
Compound of 普通 (common, general) and 法 (law), likely a direct translation of the English term 'common law'.