Champerty and maintenance

Champerty and maintenance are doctrines in common law jurisdictions that aim to preclude frivolous litigation: Maintenance is the intermeddling of a disinterested party to encourage a lawsuit. It is: "A taking in hand, a bearing up or upholding of quarrels or sides, to the disturbance of the common right." Champerty (from Old French champart) is the financial support, by a party not naturally concerned in the suit, of a plaintiff that allows them to prosecute a lawsuit on condition that, if it be brought to a successful issue, the plaintiff will repay them with a share of the proceed from the suit.

Source: Wikipedia — Champerty and maintenance (CC BY-SA 4.0)