Summary. A class action is a different animal because the certification decision, not the merits, usually determines the outcome. This toolkit is organized around that fact: the first thirty days, including CAFA removal and the preservation obligations that attach immediately; the early motions that can end or reshape the case; discovery that builds a certification record rather than a merits record; and the certification fight element by element, with attention to the damages model requirement. Later stages cover interlocutory appeal, the settlement decision, and the approval process.

What this toolkit is for, and who should use it

For a defendant, a class action is a bet on a single ruling. Before certification, the exposure is one plaintiff's claim and the cost of defending it. After certification, the exposure is the class, and the settlement value changes by orders of magnitude regardless of the merits. Everything a defendant does in the first year should be evaluated by whether it improves or worsens the certification posture.

This toolkit is written from the defense side, though a plaintiff's lawyer will find the same map useful in reverse. It assumes federal practice under Rule 23, with notes on state variations and on FLSA collective actions, which follow a different path.

Roadmap at a glance

  1. The first thirty days.
  2. Removal under CAFA.
  3. Early motions — arbitration, dismissal, standing, and strikes.
  4. Discovery strategy.
  5. The certification record.
  6. Opposing certification — element by element.
  7. Experts at certification.
  8. After the ruling — Rule 23(f), decertification, and trial planning.
  9. The settlement decision.
  10. Settlement structure and approval.
  11. Notice, claims, objectors, and fees.
  12. After judgment — release scope and repeat exposure.

Stage 1 — The first thirty days

  • Issue a litigation hold immediately and broadly. Class actions generate expansive preservation obligations, and spoliation findings poison certification and settlement alike. See Litigation Hold and Evidence Preservation Checklist.
  • Notify insurers under every policy that might respond — EPLI, D&O, cyber, media, and CGL for advertising injury. Read the consent-to-settle and panel counsel provisions before making any strategic commitment.
  • Assess exposure early with a class-size estimate and a damages model of your own. You cannot make good decisions without a number.
  • Identify the named plaintiff's file — the transaction, the account, the communications, and whether the plaintiff signed an arbitration agreement.
  • Freeze the conduct at issue where appropriate, with counsel's advice about how remediation will be characterized.
  • Check the deadline for CAFA removal, which is short and easy to miss during triage.
  • Look for parallel filings — the same firm often files similar cases in several districts, which raises consolidation, first-to-file, and MDL questions.

Stage 2 — Removal under CAFA

The Class Action Fairness Act, 28 U.S.C. §§ 1332(d), 1453, provides federal jurisdiction where the class has at least 100 members, minimal diversity exists between any class member and any defendant, and the aggregate amount in controversy exceeds $5 million.

Removal must occur within 30 days of service or of receipt of a paper from which removability is first ascertainable. The defendant's notice need only plausibly allege the amount in controversy; evidence is required only if contested. Dart Cherokee Basin Operating Co. v. Owens, 574 U.S. 81 (2014).

Anticipate the exceptions: the local controversy exception, the home state exception, and the discretionary exception, each of which turns on the citizenship composition of the class and requires the plaintiff to prove it.

Removal is usually correct for a defendant. Federal courts apply Rule 23 with more rigor than many state courts, and the Comcast damages-model requirement is more consistently enforced.

Resources

Stage 3 — Early motions

Compel arbitration. If the plaintiff agreed to arbitrate with a class waiver, this is the whole case. AT&T Mobility LLC v. Concepcion, 563 U.S. 333 (2011), and Epic Systems Corp. v. Lewis, 584 U.S. 497 (2018), make such waivers enforceable, and Lamps Plus, Inc. v. Varela, 587 U.S. 176 (2019), holds that ambiguity cannot supply consent to class arbitration. Move early, support the motion with a declaration proving what the plaintiff actually saw and clicked, and check for the exceptions — the transportation worker exemption, 9 U.S.C. § 1, and the sexual assault and harassment carve-out, 9 U.S.C. §§ 401-402. Note Coinbase, Inc. v. Bielski, 599 U.S. 736 (2023), requiring a stay of district court proceedings during an appeal from denial. Prepare for mass arbitration as the plaintiff's countermove.

Rule 12(b)(1) standing. After TransUnion LLC v. Ramirez, 594 U.S. 413 (2021), every class member must have suffered a concrete injury to recover damages. This is a certification argument as much as a pleading one: if a substantial share of the class was never injured, individualized standing inquiries can defeat predominance.

Rule 12(b)(6). Attack the elements. In consumer cases, focus on reliance, materiality, and the specificity of the alleged misrepresentation; in privacy cases, on the statutory definitions; in wage cases, on the pleading of hours worked.

Motion to strike class allegations under Rule 23(d)(1)(D) or 12(f) — rarely granted, but occasionally appropriate where the class definition is facially uncertifiable (a fail-safe class defined by liability, for example).

Be careful with picking off the named plaintiff. An unaccepted Rule 68 offer does not moot a claim, Campbell-Ewald Co. v. Gomez, 577 U.S. 153 (2016), and an attempt to buy off a plaintiff can support an adequacy argument for the other side rather than yours.

Stage 4 — Discovery strategy

Seek bifurcation of class and merits discovery. It is not always granted, and courts often find the issues intertwined, but the request frames the case as one where certification comes first.

Defense priorities in class discovery:

  • The named plaintiff's individual circumstances — the transaction, what the plaintiff saw, what the plaintiff relied on, and any atypical feature that supports a typicality or adequacy challenge.
  • The relationship between plaintiff and counsel, within the limits courts allow, on adequacy.
  • Variation across the putative class — different disclosures over time, different channels, different contract versions, different states' laws. Variation is the defense theme, because it defeats commonality and predominance.
  • The absence of injury for a meaningful subset.
  • Absent class member discovery, which courts permit sparingly and which is worth seeking on a sample where individualized issues are the theme.

Resist the plaintiff's classwide data demands as premature and disproportionate where appropriate — but recognize that a court will generally allow enough discovery to test certification, and that over-resisting produces a discovery record that hurts you at certification.

Resources

Stage 5 — The certification record

Certification requires a rigorous analysis that may overlap the merits, Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338 (2011), and the plaintiff must prove each Rule 23 requirement, not merely plead it, Comcast Corp. v. Behrend, 569 U.S. 27 (2013).

Build the record deliberately: declarations from operations personnel describing variation; documents showing different disclosures, scripts, and contract versions over the class period; data showing the distribution of outcomes across the putative class; and expert analysis on damages and on whether any classwide method exists.

Assemble absent class member declarations where they can be obtained ethically and where local rules permit, showing satisfaction, awareness, or different experiences.

Stage 6 — Opposing certification

Rule 23(a).

  • Numerosity is rarely contestable above a few dozen members.
  • Commonality requires a common contention capable of classwide resolution — "a common answer," not a common question. Dukes.
  • Typicality fails where the named plaintiff's claim depends on facts peculiar to that plaintiff, or where the plaintiff faces a unique defense — an arbitration agreement, a release, a limitations problem, or an unusual purchase channel.
  • Adequacy fails where the plaintiff's interests conflict with the class, where the plaintiff is uninvolved or uninformed, or where counsel is inadequate.

Ascertainability. Circuits differ on whether an administratively feasible method of identifying members is required. Where the class can only be identified by individual affidavits about long-ago purchases, argue it.

Rule 23(b)(3) predominance is the main battleground. Argue that individualized issues predominate on reliance, causation, injury, damages, affirmative defenses, statute of limitations, and — in multistate classes — variations in state law, which requires the plaintiff to conduct an actual analysis rather than assert uniformity.

Damages. Under Comcast, the damages model must measure only damages attributable to the plaintiff's theory of liability. Attack the model's fit, not just its accuracy. In consumer cases, test the conjoint or price-premium analysis; in wage cases, test whether representative evidence can establish classwide liability, noting Tyson Foods, Inc. v. Bouaphakeo, 577 U.S. 442 (2016), which permitted representative proof where each class member could have used it individually.

Rule 23(b)(2) classes for injunctive relief require indivisible relief; monetary relief that is not incidental belongs in (b)(3), Dukes.

Rule 23(b)(1) classes are narrow and rarely available in damages cases.

Superiority — argue the availability of individual claims with fee-shifting, an existing regulatory remedy, or a claims process the defendant already offers.

Stage 7 — Experts at certification

Expect a Daubert fight at the certification stage. Most circuits require at least a focused reliability inquiry into expert evidence offered to satisfy Rule 23. Move to exclude the plaintiff's damages expert where the model does not fit the liability theory, where it assumes rather than proves classwide impact, or where it has not been applied to the actual data.

Retain your own expert early enough to shape the discovery record, and make sure the report addresses variation across the class rather than only the merits.

Resources

Stage 8 — After the ruling

Rule 23(f) permits a petition for permission to appeal a certification order within 14 days. The deadline is strict and not extendable by a motion for reconsideration, Nutraceutical Corp. v. Lambert, 586 U.S. 188 (2019). Preserve it.

If certification is granted, consider decertification as the record develops, a motion to narrow the class definition, and trial planning — how liability and damages will actually be tried classwide is a question that often exposes the flaw in certification.

If certification is denied, evaluate whether the individual claim is worth defending or resolving, and whether a successive class action by a different plaintiff is likely. Note that China Agritech, Inc. v. Resh, 584 U.S. 732 (2018), bars a follow-on class action filed after limitations have run in reliance on American Pipe tolling.

Stage 9 — The settlement decision

Model the alternatives honestly: the cost and probability of winning certification; the exposure if certified; the cost of trial; the appellate risk; the business disruption; and the reputational effect. Then decide the timing — pre-certification settlements are cheaper but draw more scrutiny at approval; post-certification settlements are more expensive but more durable.

Consider whether a pre-suit or early claims program resolves the underlying issue at lower cost, and whether mediation with an experienced class mediator makes sense before the certification briefing.

Stage 10 — Settlement structure and approval

Structure choices: a common fund, a claims-made structure, direct payments where contact data exists, injunctive relief, and cy pres for unclaimed funds — noting judicial skepticism of cy pres-heavy settlements. Address reversion, which courts disfavor; the release scope; and the opt-out procedure.

Preliminary approval under Rule 23(e) as amended in 2018 requires the parties to provide information sufficient for the court to determine it will likely be able to certify the class and approve the settlement. Conclusory submissions are rejected. Provide the claims-rate estimate, the notice plan, the allocation formula, and the basis for the fee request.

Serve the CAFA notice on the appropriate federal and state officials within 10 days of filing the proposed settlement, 28 U.S.C. § 1715. The court cannot approve a settlement until 90 days after service, and a defective CAFA notice can allow class members to avoid the judgment later. This is a purely mechanical requirement that has undone real settlements.

Stage 11 — Notice, claims, objectors, and fees

Notice must be the best notice practicable under the circumstances, Rule 23(c)(2)(B), and may be by mail, email, publication, or digital media. Use a reputable administrator, document the plan's reach, and use plain language — courts increasingly reject notices that class members cannot understand.

Claims administration: a simple claim form, a reasonable claim period, fraud controls, and a reported claims rate. Low claims rates draw scrutiny at final approval.

Objectors: legitimate objections improve settlements; professional objectors extract payment for withdrawal. Rule 23(e)(5) now requires court approval for any payment in connection with withdrawing an objection or an appeal, which curbed the practice substantially.

Fees under Rule 23(h): percentage-of-fund or lodestar with a multiplier, briefed on notice to the class with the motion filed in time for class members to respond. Defendants generally take no position on allocation but should confirm that fees do not come out of the class recovery in a way that undermines approval.

Final approval requires a finding that the settlement is fair, reasonable, and adequate under the Rule 23(e)(2) factors: adequate representation, arm's-length negotiation, adequacy of relief considering costs, risks, delay, the effectiveness of distribution, the fee terms, and any side agreements, and equitable treatment of class members relative to each other.

Stage 12 — After judgment

Confirm the release covers what the defendant needs it to cover, and that it is coextensive with the claims that could have been brought on the same factual predicate. Track opt-outs and evaluate the residual individual exposure, which for a large opt-out group can exceed the settlement.

Then close the loop operationally: fix the practice that generated the case, document the fix, and update the compliance program. A settled class action that leaves the conduct unchanged is a subscription rather than a resolution.

Resources

Stage 13 — Variants the standard playbook does not fit

FLSA collective actions. Section 216(b) uses opt-in, not opt-out, and the standard is "similarly situated" rather than Rule 23. The traditional two-step approach — lenient conditional certification, then decertification after discovery — has been rejected by the Fifth Circuit in Swales v. KLLM Transport Services, L.L.C., 985 F.3d 430 (5th Cir. 2021), and by the Sixth Circuit in Clark v. A&L Homecare & Training Center, LLC, 68 F.4th 1003 (6th Cir. 2023), each adopting a more demanding front-end inquiry. Know your circuit's approach before the notice motion, because conditional certification is where most of these cases are decided. Note also that a hybrid case — an FLSA collective plus a Rule 23 state wage class — raises the opt-in/opt-out tension directly.

Statutory damages cases. TCPA, FCRA, FACTA, BIPA, and similar statutes create aggregate exposure untethered from actual harm. The defenses shift toward standing under TransUnion, individualized consent issues that defeat predominance, and, in extreme cases, due process arguments about aggregate statutory damages. Preserve the consent record, because consent is both the merits defense and the predominance defense.

Securities class actions follow their own track under the PSLRA: a lead plaintiff process, a heightened pleading standard for scienter, an automatic discovery stay during a motion to dismiss, and the fraud-on-the-market presumption that the defendant may rebut by showing no price impact. Halliburton Co. v. Erica P. John Fund, Inc., 573 U.S. 258 (2014); Goldman Sachs Group, Inc. v. Arkansas Teacher Retirement System, 594 U.S. 113 (2021).

Mass arbitration. A class waiver that works produces thousands of individual arbitration demands and millions in filing fees before a single merits decision. Structural responses — batching, bellwether procedures, an informal resolution period, and provider selection — must be in the agreement before the demands arrive, and must be a genuine path to resolution rather than an obstacle course, or a court will refuse to enforce them. See Website Terms of Service Review Checklist.

MDL. Where parallel cases proliferate, evaluate a motion to the Judicial Panel on Multidistrict Litigation under 28 U.S.C. § 1407. Centralization consolidates pretrial proceedings and can be a defendant's best procedural outcome, or its worst, depending on the transferee forum.

State court classes. Some state rules diverge meaningfully from Rule 23 — including on whether a damages model must fit the liability theory — which is why CAFA removal usually matters more than any single argument.

Resources

Master resource index

Articles

Checklists

Related toolkits

External and primary sources

This toolkit is educational and not legal advice. Class action practice varies by circuit and by judge, and deadlines such as CAFA removal and Rule 23(f) are strict. Consult qualified class action counsel promptly after service.