Good catch, and thank you! You were close: the chances weren't quite zero, but with high luck they got so small that they might as well have been. Luck lets you roll several times and keep the best roll, and the checks never got harder as you climbed. In the next update, luck checks get harder at higher realms, and no amount of luck makes one a sure thing. Luck still tips the odds a lot, but a late-game opportunity is a real risk again. The odds are shown on each choice, so you'll see exactly what you're gambling.