LogFAQs > #980184091

Speaking as a writer, I feel it depends on how significant the detail really is. If it's a throwaway line about something that doesn't really come up elsewhere, then I think it's fine to discard it. Better still if it can be spun as something that was misunderstood or misrepresented. But if whole character arcs or major plot events hinge on something being true, it's a problem if that thing is ignored.

Personally, I always try (but don't always succeed) to come back to any little details I might have messed up about and work that error into the story. So, like, if I say at one point that only elves can use a certain kind of magic, then forget all about that and write a dwarf using it, I might then turn around and make it ~a whole thing~ that a dwarf used this supposedly elf-only magic, and what it could mean. I'd go so far as to say that forgetting a lore detail until it's too late to fix it is a great way to add a twist that keeps the story moving~