Catalyst theory

Under the catalyst theory, a plaintiff could win attorneys' fees by showing that the lawsuit caused the defendant to voluntarily give the plaintiff what they wanted, even if the case ended without a judgment. The Supreme Court rejected the catalyst theory under most federal fee-shifting statutes in a case called Buckhannon, requiring instead a court-ordered change in legal relationship. Some states still allow the theory under their own laws, and a few federal statutes have been read to allow it. Whether catalyst theory is available depends heavily on the specific statute and jurisdiction involved. The doctrine matters because defendants sometimes settle or change course just to avoid a court order.