[SCAEUOLA libro sexto responsorum. ] §22.2.5.prPericuli pretium est et si condicione quamuis poenali non exsistente recepturus sis quod dederis et insuper aliquid praeter pecuniam, si modo in aleae speciem non cadat: ueluti ea, ex quibus condictiones nasci solent, ut 'si non manumittas', 'si non illud facias', 'si non conualuero' et cetera.
[SCAEUOLA, in the sixth book of Responses.] It is also a price of risk if, by a condition—even if it is penal—not being fulfilled, you are to receive back what you gave and, in addition, something besides the money, provided only that it does not fall under the character of a wager: as, for example, those from which claims for return (condictiones) are accustomed to arise, such as "if you do not manumit," "if you do not do that," "if I do not recover," and so forth.
nec dubitabis, si piscatori erogaturo in apparatum plurimum pecuniae dederim, ut, si cepisset, redderet, et athletae, unde se exhiberet exerceretque, ut, si uicisset, redderet.
Nor will you doubt if I should give a large amount of money to a fisherman who is about to spend it on equipment, on the condition that, if he catches fish, he should return it, or to an athlete, from which he may support and train himself, on the condition that, if he wins, he should return it.
§22.2.5.1In his autem omnibus et pactum sine stipulatione ad augendam obligationem prodest.
In all these cases, however, an agreement without a stipulation is also effective to increase the obligation.