Changeling: the Lost book states that Helldivers can dive, becoming immaterial and being able to interact with ghosts. To do that, they need to roll dexterity + occult. What happens if they fail this roll? Is it reasonable not to roll when there is no time pressure?
There's no explicit "fail forward" system in CtL2 (p.176), so a failure on the roll means that the Glamour is lost and the Helldiver doesn't start to "fade."
However, on the same page, under the guidance of "When to Roll Dice," "If your character isn’t in a stressful situation… you don’t need to roll; as long as it’s something your character could reasonably do, he just does it." So, yes, it's reasonable to not roll when there's no time or other outside pressure.