101 guide to Legal terminology

We have created the terminology guide to common legal vocabulary as it relates to social justice class actions and impact litigation. This terminology is common and used frequently in courtroom settings and in legal documents.

See, also, our The Underground Guide to Class Action Slang, Part One and Part Two.

Aggregate Proof Class Action

Evidence, typically of an economic or statistical nature, that presupposes the cohesiveness of the aggregate unit for litigation and, from that perspective, seeks to reveal quantitatively a common wrong attributable to the defendant.

Amicus Case

Latin for "friend of the court." It is advice formally offered to the court in a brief filed by an entity interested in, but not a party to, the case.

Class Action Lawsuit

A type of lawsuit in which one or several persons sue on behalf of a larger group of persons, referred to as "the class."  Subject matters of class action lawsuits can vary widely, two factors are almost always present for every class action:

  1. the issues in dispute are common to all members of the class, and
  2. the persons affected are so numerous as to make it impracticable to bring them all before the court.

Depending upon the type of class action, resolution of the lawsuit binds all members of the class certified by the Court. Under federal law, the rules governing class actions are found in Federal Rule of Civil Procedure 23.

Impact Litigation

A law suit filed to bring significant change to the nation when legislatures prove unwilling or unable to act. Impact litigation presents a chance to change the conversation where ballot measures and bills have hit a wall. It's disruptive, cutting through the noise and the politics and allowing the facts to surface.


A person who is trained and authorized in giving legal advice to clients, drafting legal documents for clients, and representing clients in legal negotiations and court proceedings such as lawsuits, and is applied to the professional services of a lawyer or attorney at law, barrister, solicitor, or civil law notary.