Actio in Factum Law and Legal Definition

Actio in factum is a legal maxim which means action on the fact. The maxim is derived from the equitable jurisdiction of the praetor where his/her duty is the interpretation and application of the law. Praetor is an annually elected magistrate of the ancient Roman Republic, ranking below but having approximately the same functions as a consul. The praetor adhere more to the facts than the application of the principles of justice.

The maxim is applied mostly in cases:

1. arising out of contracts, partnership, hiring, and sale;

2. where no special formula is provided by the civil law; and

3. where one summoned another to court without excuse.