Congress may not exercise the judicial power, see Plaut v. Spendthrift Farm, Inc., 514 U. S. 211, 218, but the legislative power permits Congress to make laws that apply retroactively to pending lawsuits, even when it effectively ensures that one side will win, Bank Markaziv. Peterson, 578 U. S. ___, ___–___. Permissible exercises of the legislative power and impermissible infringements of the judicial power are distinguished by the following rule: Congress violates Article III when it “compel[s] . . . findings or results under old law,” Robertson v. Seattle Audubon Soc., 503 U. S. 429, 438, but not when it “changes the law,” Plaut, supra, at 218. Pp.