I love megadungeons. I’ve often thought it’d be fun to design one, but balked because I’m not sure I have the chops and because of the sheer size of the undertaking. The solution to the first part of that problem is to just try it, but what about the second, the fact that it’s a big project?
So I’ve got 100 rooms to key for the dungeon. Following the distribution in the back of the Moldvay Basic rules, that breaks out as follows:
1/6 monster w/ treasure = 16-17 rooms
1/6 monster, no treasure = 16-17 rooms
1/18 trap with treasure = 5-6 rooms
1/9 trap, no treasure = 11 rooms
1/6 special = 16-17 rooms
1/18 unguarded treasure = 5-6 rooms
5/18 empty = 28 rooms
That’s 17 traps, and 17 specials. That’s where all the real work lies. Sticking a bunch of monsters in a room is easy, it’s the creative bits with traps and specials that’s hard.
And bam, just like that I realized I could design a megadungeon. I read that post yesterday, and I started designing one last night.
It’s that last part, about focusing on just a third of the rooms — the special, weird rooms — that clicked for me. Seeing the whole chart from the B/X Expert Set (paid link; my favorite version of D&D) broken out into rooms in need of keying helped, too. It’s a classic “eating the whole elephant” situation, and I’d never thought of it that way.