Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338 (2011)
Wal-Mart Stores v. Dukes is one of the Supreme Court's most consequential modern class action cases.
1) Whether the proposed nationwide class of female employees satisfied Rule 23(a)(2)'s commonality requirement where alleged discrimination arose from local managers' discretionary pay and promotion decisions. 2) Whether claims for backpay may be certified under Rule 23(b)(2), which is designed for injunctive or declaratory relief applicable to the class as a whole.
Class certification requires satisfaction of Rule 23(a): numerosity, commonality, typicality, and adequacy. For Rule 23(a)(2) commonality, plaintiffs must show not merely common questions, but a common contention capable of classwide resolution such that its truth or falsity will resolve an issue central to the claims of each member in one stroke. Courts must conduct a rigorous analysis, which may overlap with the merits, to determine whether Rule 23 is met. Under Rule 23(b)(2), certification is appropriate when the party opposing the class has acted or refused to act on grounds that apply generally to the class, making uniform injunctive or declaratory relief appropriate; individualized monetary claims that are not incidental to such relief generally cannot be certified under Rule 23(b)(2). A class action may not abridge a party's substantive rights under the Rules Enabling Act, and Title VII entitles a defendant to individualized determinations and defenses regarding backpay.
The Supreme Court reversed class certification. The proposed class failed to satisfy Rule 23(a)(2) commonality because plaintiffs did not identify a common contention whose determination would resolve a central issue for all class members. In addition, claims for backpay could not be certified under Rule 23(b)(2) because such monetary relief is not incidental to injunctive or declaratory relief and would deprive Wal-Mart of its right to individualized defenses. The Court also rejected the use of trial by formula to adjudicate backpay.
Dukes tightened the commonality requirement, insisting on a cohesive, classwide issue that can be resolved in one stroke. It authorized courts to examine merits-related evidence at certification and encouraged reliability screening of expert proof. The decision sharply limits the use of Rule 23(b)(2) for claims involving monetary relief and bars trial by formula that strips defendants of individualized defenses. Practically, plaintiffs now more often pursue narrower, tailored classes, bring claims under Rule 23(b)(3) with damages and predominance showings, or use subclasses tied to specific policies or decision-makers. For law students, Dukes is foundational for understanding how Rule 23 shapes litigation structure, evidence, and strategy.