I can see that! I've come to rely on grim favor rolls a lot when in uncharted territories. Something for terrain might be:
6: Easy to traverse
4-5: Uncertain / there's an obstacle or hazard
1-3: Critical hazard or imminent danger
Once I know how generous I'm being, I can usually decide what's plausible.
> usually decide what's plausible
The issue was that every time we thought we had a decent idea of the physical constraints, without handwaving the entire thing as ludicrous amounts of magic architecture (to our sensibilities), someone eventually noticed that it didn't work out. Not a subtle problem, more like "uh actually if you built a 3d model of what we just described there wouldn't end up being any path between the two floors".
Okay most were a bit more subtle than that one. But that one did happen.
