VOCATIO IN JUS, Roman civ. law. According to the practice in the legis actiones of the Roman law, a person having a demand against another, verbally cited him to go with him to the praetor in jus eamus. In jus te voco. This was denominated vocatio in jus. If a person thus summoned refused to go, he could be compelled by force to do so unless he found a vindex, that is, a procurator or a person to undertake his cause. When the parties appeared before the praetor, they went through the particular formalities required by the action applicable to the cause. If the cause was not ended the same day, the parties promised to appear again at another day, which was called vadimonium. See Mat h.v. 25.