1. In diem addictio

(a) Functions

"In diem addictio ita fit: 'ille fundus centum esto tibi emptus, nisi si quis intra kalendas lanuarias proximas meliorem condicionem fecerit, quo res a domino abeat'."¹³⁰ This was the standard way¹³¹ of phrasing an in diem addictio: let the land be sold to you, unless someone makes a better offer before the first of January next, on account of which the land departs from its owner.

(b) Construction

Was this particular type of pactum adiectum to be construed as a resolutive or rather as a suspensive condition?^[3759] Julian appears to have opined in favour of the former alternative,^[3760] Pomponius in favour of the latter.^{[3761] [3762] Ulpian gave the typical lawyer's answer: it depends —}

"[qjuotiens fundus in diem addicitur, utrum pura emptio est, sed sub condicione resolvitur, an vero condicionalis sit magis emptio, quaestionis est.

The decisive criterion was thus the intention of the parties. If they wanted performance and counterperformance to be rendered immedi­ately, then what they had in mind was "pura emptio, quae sub condicione resolvitur"; if, on the other hand, they wished to defer the implementation of their transaction until either a better offer had been made or the time set for the receipt of a better offer had elapsed, the sale was obviously "condicionalis". What the matter usually boiled down to, in the end, was which of the two parties had been able to prevail with his ideas concerning how the contract was to operate: the purchaser, as a rule, being interested in a resolutive condition (since he would then immediately receive the object of the sale), the vendor normally favouring suspension of the contract (for as long as he was still in possession of the object he had a greater chance of finding third parties interested in acquiring it).

(c) Interpretation

But even apart from that, in diem addictiones offered the Roman jurists plenty of scope to display their interpretive skills.^{[3763] [3764] [3765] [3766] [3767] [3768] [3769] Taking the typical intentions of reasonable Roman purchasers and vendors as their starting point, they worked out a refined and well-balanced set of principles. Generally speaking, they tended to favour the purchaser—quite in accordance with the notion that ambiguous terms should be interpreted to the disadvantage of the party that had (typically) introduced them into the transaction.138 Any doubt, for instance, as to whether the condition had been satisfied was held against the vendor; if two slaves had been sold separately to two purchasers for ten apiece and someone offered thirty for the two, the sale was not dissolved as long as it remained uncertain for which of the slaves, if not for both, a better offer had been made.139 Furthermore, the purchaser was normally allowed to solicit, and accept, only one better offer.140 Whether or not in the end he accepted it, was left to his discretion; he was perfectly free to stand by the original contract.141 If, however, he decided to take up the second offer, he had to inform the (first) purchaser, so as to give him a chance to improve his own bid;142 and provided the first purchaser was prepared to match the second offer, the vendor could not call off the sale.143 The crucial question, obviously, in many cases was, under which circumstances the second offer could be regarded as "melior condicio".}

2.