Federal Question Jurisdiction
Federal court power over cases that arise under the U.S. Constitution, federal statutes, or treaties.
Governing rule: 28 U.S.C. § 1331
Plain-English definition
Federal question jurisdiction is what lets a case start in federal court because the plaintiff is relying on federal law, not just state law. The federal issue must appear on the face of the well-pleaded complaint. A defense based on federal law usually is not enough by itself to create federal question jurisdiction.
How it works
The court checks federal question jurisdiction at the beginning of the case and can revisit it later. If the complaint does not actually arise under federal law, the federal court must dismiss or remand the case.
Why it matters
Jurisdiction decides which courthouse hears the dispute. A federal forum can change the judge, procedural rules, jury pool, timing, and appeal path.