Rule 23(a) establishes four prerequisites: numerosity, commonality, typicality, and adequacy of representation. Rule 23(b) defines the class types, including 23(b)(2) classes seeking injunctive or declaratory relief and 23(b)(3) damages classes requiring predominance and superiority.
Rule 23(f) permits discretionary interlocutory appeal of certification decisions.
Alternative Names:
Federal Rule 23, Class Certification Rule
Why it Matters?
The subdivision matters as much as the prerequisites, because 23(b)(3) damages classes carry notice and opt-out rights and require predominance, while 23(b)(2) injunctive classes do not. Plaintiffs sometimes seek 23(b)(2) certification for classes that are functionally seeking money, and challenging that characterization is a standard and often successful defense.
Frequently Confused with
Related terms
Frequently asked questions
What are the Rule 23(a) prerequisites?
Why does the class type matter?
