Justinian 1st specifies a requirement (obligatio) throughout his / her Institutiones, Ebook 3, section 13 seeing that "a appropriate relationship, together with which often we're bound simply by must regarding performing a number of take action according to the legislation of our own Talk about. " He additionally sets apart legal issues regarding bills directly into legal agreements, delicts, quasi-contracts, along with quasi-delicts.
These days, requirement, seeing that applied below civilian law, means any appropriate wrap (vinculum iuris) with which several celebrations (obligants) are usually bound to complete or refrain from performing specified execute (prestation).  Hence a requirement features both facets in the picture, both obligor's obligation to help give prestation as well as the obligee's right to be given prestation. The idea varies from your common-law notion of requirement which often just features the work factor.