Apologies for the lack of posting lately, I've been sick and somewhat run down. Work and illness have been interfering with my gaming, and the latest Fallout installment has been sucking up a lot of my attention as well.
But I've been a doing a bunch of work on my Algol megadungeon. At this point, I have the following mapped out:
Level 1 - 143 rooms
Level 2 - 144 rooms
Level 2.B - 39 rooms
Level 3 - 82 rooms
Level 3.B - 9 rooms
Level 3.B.3 through to 3.B.7 - 34 rooms
Level 4.A - 28 rooms
Level 4.B - 22 rooms
Level 4.C - 22 rooms
The level labeling system is kind of funky right now; the oddball named levels are sub-levels or sub-complexes within the megadungeon. Of course there are byzantine interconnections between the levels.
I've paid attention to the erudite Gabor Lux's past works analyzing dungeon construction and flow, and the big levels are designed with that in mind by incorporating "loops" within the dungeon avenues. In effect there are several "neighborhoods" within each main level, as well as "freeways," complexes of corridors that allow one to travel throughout much of the differing areas of the level without having to deal with doors or major barriers; thereby allowing the giant worms and flying jellyfish means of traversing the dungeon.
A big influence has been Empire of the Petal Throne's Underworld and megadungeon innovator M.A.R. Barker's work. For my own game, one of the tentpoles of the megadungeon monster stocking will be from D&D variant EPT. The other three tentpoles being Carcosa, Arduin and the original Fiend Folio (including White Dwarf FF content), with some cherry picking from Talislanta. In any published version most such critters would be replaced with original or OGL content, but in my own game I get to use Gorbels without turning them into little exploding, clinging toddler-robots first.
As an aside, I've read previous online musings about using the Fiend Folio as an alternate Monster Manual instead of the aforementioned MM, and I have to say, I can see it working. There's definitely a nice range of humanoids in the kobold-equivalent to ogre-equivalent spectrum. Plus, forget everything you know about Gibberlings and read them with through a pulp Swords & Sorcery lens.
I'm going with a sparse monster distribution, with 1 "encounter" for every six rooms or so; with allowances for some encounter groups controlling several rooms. The general vibe I'm going for with this aspect is vastly ancient, abandoned decrepitude punctuated with moments of terror. With pockets of really bad areas.
At the 1-to-6 monsters placement-to-room ration, it works out to 24 monster encounters for the first two levels...which is quite a lot, and leaves me with a lot of room on my plate for the Tekumel/Arduin/Carcosa/Fiend Folio buffet...