Assumpsit

Assumpsit ("he has undertaken," from Latin, assumere) is an action for the recovery of damages caused by the breach or non-performance of a simple contract, either express or implied, and whether made orally or in writing.

In the United States, assumpsit, like the other forms of action, became obsolete in the federal courts after the adoption of the Federal Rules of Civil Procedure in 1938. Most states have moved to similar rules, which replace the various forms of action with a civil action. However, many states continue to recognize assumpsit as a common law or statutory cause of action.