Champerty (Lat. campi partitio), an agreement between a party to a suit and some third person that the latter shall carry on the suit at his own expense, and in consideration thereof shall receive a portion of what is recovered therein in case of a successful result. It differs from maintenance in that in the latter case the question of compensation does not necessarily enter into the account. At the common law, not only was the agreement void, but the entering into it was a misdemeanor, and statutes were passed to punish cases analogous in character and in supposed mischief. Of late, however, the tendency has been to relax the old rules, from a conviction that, whatever may have been the case formerly, the evils that might flow from such bargains are rather imaginary than real. By statute in some of the United States it is legal for a party to make such bargain with his attorney as he may consider for his interest; and judicial decisions have modified the old rules considerably where no such statutes exist.

It was a very ancient rule of the common law that choses in action should not be assigned, the object of which rule was to prevent any champertious intermeddling with claims to be put in suit; but courts of equity long since recognized the right of the assignee, and no other effect of the rule remained except that it was required that a suit at law should be brought in the name of the assignor. But this has now been abrogated in a number of the states, and assignees may sue at law in their own names, subject, however, to all legal defences and offsets which existed against the claim in the hands of the assignor at the time of notice of the assignment.