Mass tort or class action: what's the difference?

Two ways courts handle harm to many people

A tort is a civil wrong that causes harm, like an injury from a defective product. When the same product or conduct harms many people, courts have two common approaches: individual lawsuits grouped for efficiency, or a single class action.

How a mass tort works

In a mass tort, each injured person files a separate lawsuit. Federal cases may be grouped into a multidistrict litigation (MDL) for pretrial work, but each case keeps its own facts.

This matters because injuries differ. Two people who used the same drug can have different diagnoses, medical costs, and lost income, so each person's damages depend on their own records.

How a class action works

In a federal class action, one or more people sue on behalf of everyone in a defined group. Rule 23 of the Federal Rules of Civil Procedure requires the court to certify the class first, after checking four things:

• Numerosity: the group is too large for everyone to join the case individually
• Commonality: the members share questions of law or fact
• Typicality: the representatives' claims are typical of the group's claims
• Adequacy: the representatives will fairly protect the group's interests

A judgment or court-approved settlement binds the class members. In class actions for money damages, members must get notice and can ask to be excluded.

The differences side by side

Here's how the two compare on the points that affect you most:

• Your case: in a mass tort, you have your own lawsuit. In a class action, a representative sues for the whole group
• Damages: in a mass tort, they're based on your own injuries and records. In a class action, they're set by the judgment or settlement terms for the class
• Decisions: in a mass tort, you decide with your lawyer whether to accept a settlement offer. In a class action, the court approves a settlement for everyone, and members can object or opt out where the rules allow

Why injury cases are rarely class actions

Rule 23 depends on common questions holding the group together. Personal injuries differ from person to person, which makes those requirements hard to meet. That's why product-injury claims are commonly filed as individual lawsuits and grouped in an MDL.