The U.S. Supreme Court has agreed to hear Wal-Mart’s appeal of a Ninth Circuit decision allowing a massive class-action discrimination suit against the company to go forward. The lawsuit, alleging nationwide violations of Title VII’s prohibition on gender discrimination, was certified as a class-action covering a record-breaking 1.5 million current and former Wal-Mart employees. The decision should affect how broadly classes can be defined and what relief is available under class-action lawsuits to the covered class. This will have significant consequences for the future of civil rights litigation in the employment discrimination context, as the ruling could help–or hinder–future efforts to sue companies that engage in discrimination that is widespread but hard to prove.