This is a tricky one, I have been wrestling with this conceptually for literally years now, but Just now I had an revelation. I have been working from the wrong end!
I was seeing the Dungeon as a growing thing, like a plant. You put a seed down and a sprout turns into a plant that grows into a tree. But as all dungeons are a part of the DungeonGod this allegory don’t work well.
Instead I have to work the other way around, something calls upon DungeonGod and a tendril sprouts forth and begin to manifest a Dungeon. These manifests as Lairs of Mosters. Contary to what I thought before Lairs do not grow into dungeons by adding levels underneath it. Instead it contains clues to an dungeon entrance.
So how do Lairs get created? Well, now we run into a hen and egg problem so I have to go back to another idea, namely the “traps as the flowers of dungeons” concept. Traps are “grown” by Dungeons and always contains a magical item, like the honey of flowers. The Dungeon rewards the conflict participant (either being victim of or trying to disarm the trap) with a magical item. Well these items griws (scales) with the hero but at one point or another they will certainly be stored somewhere due to the hero retiring or abandoning the item in favor of another magical thing (I plan to enforce the no more than seven magical item rule or something similar). When the magical items stays to long in one place they begin to summon Lairs.
When the Lairs get raided they in turn summons Dungeons of Level 1. After enough conflicts there will open entrances to deeper levels, this could be sink holes opens, secret doors found or just mining creatures opening up new ways.
The structure of a Dungeon should always be like a stair with each new depth having an unexplored back entrance for the heroes to find and giving them a faster rout to the deeper Dungeon. The DungeonGod wants to facilitate stronger Heroes meeting stronger opponents to have the conflicts drawn out and thus power generating as possible.
The procedurally generated first level dungeons can be further and further apart as the dungeons isn’t actually a part of the world but “inside” Dungeon’God and could span any distance, even to other worlds if it suits the story. I would have the distance grow with each deeper level and in the deeper end bring in other worlds just to keep it interesting.
Also these new dungeons should appear where there are lairs…. And grow their own deeper levels. Making a never ending network of dungeons.
The question is .. What awaits in the deepest level … Level 20?
… Don’t know how much sense this make, but it is finally a structure to build on.