Which item is NOT a Rule 23 prerequisite for class certification?

Which item is NOT a Rule 23 prerequisite for class certification?

• A. Numerosity.
• B. Commonality.
• C. Typicality.
• D. Res judicata.

Answer: (D)

Rule 23 certification hinges on four requirements: numerosity, commonality, typicality, and adequacy of representation. Numerosity means there are so many potential class members that joinder is impracticable. Commonality requires questions of law or fact to be common to the class. Typicality ensures the representative's claims or defenses arise from the same event or course of conduct as the class claims. Adequacy covers the ability of the representative to fairly and adequately protect the interests of the class. Res judicata, on the other hand, is a separate doctrine of claim preclusion that bars relitigation of claims already adjudicated. It does not determine whether a class meets Rule 23’s prerequisites. So it is not a prerequisite for class certification.

Rule 23 certification hinges on four requirements: numerosity, commonality, typicality, and adequacy of representation. Numerosity means there are so many potential class members that joinder is impracticable. Commonality requires questions of law or fact to be common to the class. Typicality ensures the representative's claims or defenses arise from the same event or course of conduct as the class claims. Adequacy covers the ability of the representative to fairly and adequately protect the interests of the class.

Res judicata, on the other hand, is a separate doctrine of claim preclusion that bars relitigation of claims already adjudicated. It does not determine whether a class meets Rule 23’s prerequisites. So it is not a prerequisite for class certification.