Noun
substantive law (uncountable)
(law) The statutory or written law that governs rights and obligations of those who are subject to it.
So great is the ascendancy of the Law of Actions in the infancy of Courts of Justice, that substantive law has at first the look of being gradually secreted in the interstices of procedure; and the early lawyer can only see the law through the envelope of its technical forms. Henry James Sumner Maine
And the Ifugao developed a very elaborate system of substantive law. Source: Internet
Erie overruled Swift v. Tyson, and instead held that federal courts exercising diversity jurisdiction had to use all of the same substantive law as the courts of the states in which they were located. Source: Internet
Moreover, in American law, the Erie doctrine requires federal courts sitting in diversity actions to apply state substantive law, but in a manner consistent with how the court believes the state's highest court would rule in that case. Source: Internet