Thoroughly unsettling! I'd like to run this one. The NPCs have just enough detail to riff off of and play them, and have a strong motivation to steer their actions. I feel like it could be easily adapted to a western setting as well.
Thanks for the feedback! I realized there were some missing connections on my map and the routes in/out weren't marked, which I think reduces the linearity. I also had cut the description of the exterior which hints at the second entrance, which I've now added back in. I do agree though, it turned out more linear than I wanted / expected.
On the magma level rising, it will never actually inundate level 3, although I can see where the confusion comes from. I added some notes to the delving rules section to hopefully clarify.
Really well written. I like the simultaneous extreme reward and extreme danger to be found. The magic items are really clever, and as others have stated the unpredictability of NPC locations is a nice touch that lets the GM play to find out as well.
Thanks for the feedback! Since you mention it, I completely agree that I need to work on terseness. I might do another editing pass when art gets added.
