A more thorough explanation:

Definition: Campipartia is another term for champerty, which is an agreement between someone who is not involved in a lawsuit and a litigant. The agreement involves the outsider helping the litigant pursue their claim in exchange for a portion of any money awarded in the lawsuit. This is also known as splitting the field.

For example, if someone is involved in a lawsuit and they need financial help to continue with the case, an outsider may offer to help them in exchange for a portion of any money awarded in the lawsuit. This is considered champerty or campipartia.

There is some disagreement among American courts about what constitutes champerty. Some courts believe that an agreement to receive compensation from the proceeds of the lawsuit is enough to be considered champerty. Other courts believe that the attorney must also pay for the lawsuit's costs and expenses to be considered champerty. However, most courts agree that a contract for a contingent fee is not champerty if it is not paid out of the lawsuit's proceeds.

Historically, champerty was also a writ available to the party who was the target of a champertous action. This writ was used when two people were involved in a lawsuit, and one gave part of their claim to a stranger to help them win the lawsuit against the other person. The party who was wronged could use the champerty writ to take legal action against the outsider who helped the other party.