Well-Pleaded Complaint Rule
well-pleaded complaint rule n: a rule of procedure that federal question jurisdiction cannot be acquired over a case unless an issue of federal law appears on the face of a properly pleaded complaint NOTE: The well-pleaded complaint rule is not satisfied by a defense based on federal law, including a defense of federal preemption, or by anticipation of such a defense in the complaint.
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.