The merger doctrine in civil procedure stands for the proposition that when litigants agree to a settlement, and then seek to have their settlement incorporated into a court order, the court order actually extinguishes the settlement and replaces it with the authority of the court to supervise the behavior of the parties.^[1] Under this doctrine, the court is free to modify its order as necessary to achieve justice in the case, and may hold a party that breaches the agreement in contempt of court.

In U.S criminal law, merger doctrine holds that if a defendant has committed acts that simultaneously meet the elements of a more serious and less serious offense, the defendant may be charged with the more serious offense and the lesser offense drops in order to avoid implicating double jeopardy.^[2]