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.

In Missouri, barratry, maintenance, and champerty are considered misconduct in the legal profession. Barratry, which involves the improper solicitation of clients by an attorney, is prohibited and can lead to criminal charges as well as professional disciplinary action against the attorney. Missouri law specifically prohibits attorneys from engaging in conduct that involves dishonesty, fraud, deceit, or misrepresentation, which would include barratry. Maintenance and champerty, while not as commonly prosecuted, involve third-party interference in litigation. Maintenance refers to the support of litigation by a third party with no legitimate interest in the case, and champerty involves a third party financing a lawsuit in exchange for a portion of the proceeds. While these practices may not be explicitly outlined in Missouri's statutes as criminal offenses, they can still result in professional disciplinary action against attorneys and may be addressed in civil court. It is important for attorneys to avoid any actions that could be construed as barratry, maintenance, or champerty to maintain their professional standing and avoid legal repercussions.