classaction

A class action is a lawsuit in which one or more plaintiffs sue on behalf of a larger group of people who have similar claims. The class action mechanism allows individual claims that might be too small to litigate efficiently to be resolved together, leveraging economies of scale and ensuring consistent judgments.

In the United States, class actions are principally governed by Rule 23 of the Federal Rules of Civil Procedure, though many states have parallel rules. Other jurisdictions have analogous procedures. To certify a class, courts typically assess factors such as numerosity (the class is large enough that joinder is impractical), commonality (the claims involve common questions of law or fact), typicality (the representatives' claims are typical of the class), and adequacy of representation (the representatives will fairly and adequately protect the class’s interests). Courts also consider predominance of common issues and the superiority of a class mechanism over individual suits.

If certified, class members are notified and may be bound by the outcome. Members who wish to pursue their own actions may opt out in some schemes; others may be bound by the result even without filing individually. Settlements or judgments typically require court approval to protect the class and ensure fair compensation.

Class actions can address a range of issues, including consumer, employment, securities, antitrust, and product liability claims. They offer efficiency and risk-sharing benefits but also face criticisms about potential unfair settlements, control by named plaintiffs, and lengthy procedures.