In the Wal-Mart case, the Supreme Court decided against allowing a class-action lawsuit on behalf of 1.5 million female employees alleging gender discrimination in pay and promotion. The Court ruled that the plaintiffs failed to demonstrate a commonality of claims necessary for a class-action suit, as required by Federal Rule of Civil Procedure 23. The decision emphasized that commonality requires more than just the presence of a common question; it necessitates a common answer that can drive the resolution of the entire case. In this case, the Court found that the plaintiffs’ claims lacked the required commonality because they did not share a common policy that could be challenged as discriminatory.