Hey, thank you for checking the game :) Some things “happens” but since there is no feedback about it in the game you cannot know it ! Every night, the adventurers without a quest take a look at thoses availables and try to pick them up, but there’s a few rng involved and a difficulty scaling. Since the base adventurers aren’t so great, if you picked a diamond as a reward, this boost the quest difficulty too much and essentially make it unselectable by the early game adventurers.