Barratry is the improper solicitation of a client done by or on behalf of an attorney and is a criminal offense in most states. The filing of a lawsuit or other legal complaint without the permission of the named plaintiff or complainant may also constitute barratry. And a judge who accepts a bribe in exchange for a favorable decision may be guilty of barratry.
Maintenance refers to improper assistance in prosecuting or defending a lawsuit, provided by someone who has no legitimate interest in the case—also known as meddling in someone else's litigation.
And champerty is an agreement between a litigant and an intermeddler in a lawsuit in which the intermeddler helps the litigant pursue the claim in exchange for receiving part of any settlement or judgment in the litigation.
Laws regarding barratry, maintenance, and champerty vary from state to state and are usually located in a state's statutes—often in the penal code or criminal code. Barratry is illegal in all states, with criminal prosecution and state licensing implications for attorneys who engage in the practice. But the maintenance and champerty doctrines are not recognized in all states.