In the Wal-Mart Stores, Inc. v. Dukes (2011) case, the U.S. Supreme Court ruled that a class- action lawsuit filed by female employees claiming gender discrimination at Wal-Mart could not proceed. The key reason for the Court’s decision was the failure to meet the “commonality” requirement for class actions. This legal term means that for a class to be certified, the plaintiffs must show that they share common legal or factual questions that can be resolved in a single trial. The Court concluded that plaintiffs failed to prove commonality because their claims were too diverse: the employees worked for different managers, in different regions, with different experiences. Wal-Mart’s management system was so decentralized that there was no company wide policy or practice affecting all employees similarly. Thus, the case could not be maintained as a class action.