Cite as: 603 U. S. ____ (2024) 11 THOMAS, J., concurring in judgment a statute is valid on its face, a court must determine the statute’s scope. If a state court has yet to determine the scope of its statute (a common occurrence with facial challenges), the federal court must do so in the first instance. Facial challenges thus increase the likelihood that federal courts must interpret novel state-law questions—a role typically and appropriately reserved for state courts. B In addition to their constitutional infirmities, facial challenges also create practical problems. The case-or-controversy requirement serves as the foundation of our adversarial system. Rather than “ ‘sit[ting] as self-directed boards of legal inquiry and research,’ ” federal courts serve as “ ‘arbiters of legal questions presented and argued by the parties before them.’ ” NASA v. Nelson, 562 U. S. 134, 147, n. 10 (2011) (quoting Carducci v. Regan, 714 F. 2d 171, 177 (CADC 1983) (opinion for the court by Scalia, J.)). This system “assure[s] that the legal questions presented to the court will be resolved . . . in a concrete factual context conducive to a realistic appreciation of the consequences of judicial action.” Valley Forge Christian College v. Americans United for Separation of Church and State, Inc., 454 U. S. 464, 472 (1982). Facial challenges disrupt the adversarial system and increase the risk of judicial error as a result. A plaintiff raising a facial challenge need not have any direct knowledge of how the statute applies to others. In fact, since a facial challenge may be brought before a statute has been enforced against anyone, a plaintiff often can only guess how the statute operates—even in his own case. For this reason, “[c]laims of facial invalidity often rest on speculation,” Washington State Grange, 552 U. S., at 450, and “factually barebones records,” Sabri v. United States, 541 U. S. 600, 609 (2004). Federal courts are often called to give “prema-