In the Wal-Mart case, the Supreme Court made a ruling on a class-action lawsuit that had been filed by female employees who claimed gender discrimination. The Court found that the lawsuit couldn’t proceed as a single class-action due to the lack of commonality among the female employees. This means that they didn’t share enough common legal or factual issues. The Court emphasized that commonality is a prerequisite for class certification, as per Rule 23 of the Federal Rules of Civil Procedure. The female employees worked in different job positions and locations, making it impossible to pursue their claims collectively through a class-action lawsuit. Therefore, each employee’s claim had to be pursued individually.