Changes how plaintiffs prove discrimination under federal civil‑rights laws by allowing a showing that a protected trait (for example, age, race, or disability) was a motivating factor in an adverse action even if other factors also played a role. It defines the new proof standard, permits many forms of evidence, and limits remedies when the defendant proves it would have taken the same action for legitimate reasons. The change applies to Title VII, the Age Discrimination in Employment Act, the Americans with Disabilities Act, and the Rehabilitation Act, and it applies to any claim still unresolved when the law is enacted. A severability rule preserves the rest of the law if any part is struck down by a court.