So I've been following the Domain rules thread, which in turn brought me to the old
Converting ACKS Domains to 3E thread from 2015, which even though it was never finished
as a domain game has still been a useful demographic resource for me, because I'm the kind of GM who gets a bit obsessive about things like that.
And so I had a question - there are table entries there for extracting extra resources for your domain
from the Underdark, but what would be a reasonable set of assumptions for a domain that's entirely
in the Underdark, like the Drow or Deep Gnomes or something?
This would be a version that's fantastical enough that you can sustain towns and farms and stuff down there
at all, but not one that's all mushroom forests and glowing crystals - things are pretty bleak.
So to a first approximation, the Underdark is basically barren desert, and the only places that can be farmed are hexes that have food caverns and similar resources. Plus a lot of your hex is taken up by
solid rock.
On the other hand, your hexes are
three-dimensional, giving you potentially a lot more space to exploit. (Two-dimensional hex mapping in the underdark doesn't really make a lot of sense to begin with, but it's useful enough for hexcrawling and domain management that I submit you just think of the map as an abstraction of routes through a three-dimensional complex.)
So my initial thought is that this all shakes out to most Underdark hexes having an arable land value of 10%, and a Fertility of 10 (or rather 12,5 when you're working on the metric system and counting from 25 rather than 20 koku per farm. Either way, it's a 50% yield).
Now this allows a tiny amount of surplus, but not a whole lot. Farmers in the Underdark are basically Oppressed Serfs just by virtue of where they live, and the landholders aren't much better off:
8000 hectares per hex times 10% arable land makes 80 farms per hex.
25 Koku per farm times 50% yield times those 80 farms makes 1000 koku per hex.
Farmers needing to eat means a surplus of 600 koku per hex.
So there flat out isn't enough surplus for farmers to be better off than Oppressed Serfs on the surface, and even that yields the landlord only 300 koku per hex of farmland.
Is that right?
Granted most of the Underdark dwellers are more awesome than your average humans, so they'll have things like Clerics casting Create Food to supplement food production, but that's on the level of adding a handful of farms per Cleric. (I suppose they might have Druids for Plant Growth, which scales much better, but a lot of the civilizations down there don't have much nice to say about Druids.) Disregarding such ways to bring more food to the cities for now, are there any other factors (or system elements) I've overlooked for better or worse or is the Underdark really as barren as my calculations suggest?
It doesn't seem unreasonable by any means but I was hoping there might be some factor that would allow a greater surplus - Underdark towns are probably
small but they should be highly developed with enchanted castles and spider cavalry and shit.
