A mass tort is a civil lawsuit that involves hundreds or thousands of plaintiffs and one or a few defendants in which the plaintiffs have the same or similar claims against the defendant or defendants. Mass tort lawsuits are often filed as class action lawsuits (a procedural mechanism for joining the plaintiffs in one lawsuit), and are typically based on alleged wrongful acts (torts) such as exposure of the plaintiffs to harmful substances (asbestos or benzene), or defective products (pharmaceuticals or medical devices), or invasions of privacy (data breaches).

In Minnesota, as in other states, a mass tort is a type of civil action that involves numerous plaintiffs against one or several defendants. These plaintiffs usually have similar legal issues or have been harmed in a similar fashion by the defendant's actions. Mass torts often arise from exposure to harmful substances, defective products, or large-scale invasions of privacy such as data breaches. In Minnesota, these cases can be managed through a class action mechanism if they meet certain criteria, such as a large number of plaintiffs, common questions of law or fact, typical claims or defenses of the class, and a representative party that will fairly and adequately protect the interests of the class. These criteria are outlined in the Minnesota Rules of Civil Procedure, Rule 23. Mass torts are complex and require coordination among the parties and the court, and they may be consolidated for pretrial proceedings to streamline the legal process. It's important to note that while mass torts can be filed as class actions, not all mass torts will qualify as class actions, and they may proceed as individual lawsuits that are coordinated or consolidated for judicial efficiency.