Lex non scripta is a Latin expression that means "'law not written'" or "'unwritten law'". It is a term that embraces all the laws which do not come under the definition of written law or "lex scripta"^[1] [i.e.statutory law, created by a governing body^[2]]. it is composed, principally, of the law of nature, the law of nations, the common law,^[3] and customs.

• List of Latin phrases
• Unspoken rule