The actual terms of success or failure were not stated on-page; the band of adventurers did successfully penetrate Yre's defenses. So did they make a bet on something like 'You will not be able to breach the treasure vault of the Grand Dragon' (pulled it off, albeit with casualties) or 'You will not be able to recover your boyfriend from Yre' (a fixed bet from the start, as it turns out he wasn't even there?)