From his master's legal capacity a slave derives ability to be promisee in a stipulation. Thus, as an inheritance in most matters represents the legal 'person' of the deceased, whatever a slave belonging to it stipulates for, before the inheritance is accepted, he acquires for the inheritance, and so for the person who subsequently becomes heir.
1 All that a slave acquires by a stipulation he acquires for his master only, whether it was to that master, or himself, or his fellow slave, or no one in particular that performance was to be made under the contract; and the same principle applies to children in power, so far as they now are instruments of acquisition for their father.
2 When, however, what is stipulated for is permission to do some specific act, that permission cannot extend beyond the person of the promisee: for instance, if a slave stipulates for permission to cross the promisor's land, he cannot himself be denied passage, though his master can.
3 A stipulation by a slave belonging to joint owners enures to the benefit of all of them in proportion to the shares in which they own him, unless he stipulated at the bidding, or expressly in favour, of one of them only, in which case that one alone is benefited. Where a jointly owned slave stipulates for the transfer of property which cannot be acquired for one of his two masters, the contract enures to the benefit of the other only: for instance, where the stipulation is for the transfer of a thing which already belongs to one of them.
TITLE XVIII. OF THE DIFFERENT KINDS OF STIPULATIONS
Stipulations are either judicial, praetorian, conventional, or common: by the latter being meant those which are both praetorian and judicial.
1 Judicial stipulations are those which it is simply part of the judge's duty to require; for instance, security against fraud, or for the pursuit of a runaway slave, or (in default) for payment of his value.
2 Those are praetorian, which the praetor is bound to exact simply in virtue of his magisterial functions; for instance, security against apprehended damage, or for payment of legacies by an heir. Under praetorian stipulations we must include also those directed by the aedile, for these too are based upon jurisdiction.
3 Conventional stipulations are those which arise merely from the agreement of the parties, apart from any direction of a judge or of the praetor, and which one may almost say are of as many different kinds as there are conceivable objects to a contract.