If we operate under the assumption that the underworld, or specifically your campaign's megadungeon, has been attracting adventurers for a lengthy period of time, it is not a stretch of the imagination to realize that there are more than likely going to be a number of delvers assumed dead that are in fact trapped in limbo in the dark confines below.
In your standard campaign such a form of stasis could occur through your run of the mill flesh to stone attack. Characters with a CON of 13 or more will automatically survive such an ordeal, and are quite literally waiting for the right Magic User to come along and rescue them. In the Bleak Beyond other such means of imprisonment include being turned to glass, turned to a scarecrow, time-locked, frozen solid and gem-prisoned.
Any unfortunate character missing his save against such a threat must make a survival roll based on his or her CON score. Those succeeding are still often “lost to the underworld” even though they are not quite dead yet. Thus the Bleak Beyond includes a category of magic items called Lost Heroes. Perhaps the most potent of all magic items in my dungeon as of this writing since I have yet to flesh out any relics or artifacts, these Lost Heroes will pledge loyalty and serve their rescuers for a time and could even become player characters as the campaign unfolds.
Although you might not handle flesh to stone in the same fashion, the concept of Lost Heroes as magic items can still be used in your games by adding a few new features to your dungeon.
This is an example of the many Bleak Beyond tidbits I plan to assemble and include in the final megadungeon project. Along with the PDF's I've shared this year; Monster Business, Random Monster Tables, d6 Dungeon Rooms, 100 NPC Types and Dungeon Treasure Maps (I have a BB-centric version), these supplemental pieces will eventually work together to form the framework upon which the megadungeon will operate.
The d00 Stairways table was one I planned to rework and include, BUT I've come to the design decision that I will henceforth be treating stairways as rooms unto themselves, in other words each will be numbered and keyed. Duh. That's something I should have been doing all along. Something so obvious!
So while this particular document is Bleak Beyond material and written as such, you still might get some use or inspiration out of it. You will find it in the expanding SHAM'S OD&D STUFF section to the right.
Here's a copy and paste of the 24 known Lost Heroes in case you don't wanna down load the PDF.
Lost Heroes of the Bleak Beyond
Roll d24 if you want a random Lost Hero (d12+d6, odd on d6 add 0 to the d12, even on d6 add 12). Lost Heroes are never found on a dungeon level with a value less than their experience level.
1. Wigwaite FM 4, Male, L, S: 15, C: 16, Spear +1. Turned to Stone.
2. Dianedrio Elf FM 4, Male, L, S: 15, C: 13, Displacer Cloak. Morphed to Scarecrow.
3. Big Sal Hobbit 4, Male, S: 14, C: 15, Plate +1. Gem-Prisoned.
4. Cheburov Dvergar 4, Male, N, S: 17, C: 14, Sword +1. Turned to Stone.
5. Tillanaith FM 5, Female, N, S: 14, C: 13, Magic Bow. Time-Locked.
6. Hibu Dae MU 5, Male, N, I: 15, C: 14, Wand of Cold. Morphed to Scarecrow.
7. Janolare C 5, Female, L, W: 17, C: 13, Staff of Healing. Turned to Stone.
8. Thump LeBump Dwarf 5, Male, L, S: 13, C: 17, Axe +1. Turned to Stone.
9. Fendryal Aelfar MU 5, Male, N, I: 14, C: 13, Wand of Paralization. Time-Locked.
10. Glipnart Doende 5, Female, N, S: 14, C: 15, Ring of Protection. Turned to Glass.
11. Kippy Bitz Irkling 5, Male, N, W: 16, C: 14, Snake Staff. Gem-Prisoned.
12. Kimbobol Dwarf 6, Female, L, S: 16, C: 14, War Hammer +1. Gem-Prisoned.
13. Oxblatt Dwarf 6, Male, L, S: 14, C: 15, Ring of Protection. Time-Locked.
14. Kucharel Aelfar FM 6, Female, N, S: 16, C: 13, Spear +2. Frozen Solid.
15. Haxlo Dvergar 6, Male, N, S: 16, C: 17, Mace +2. Morphed to Scarecrow.
16. Rugmeister Doende 6, Male, N, S: 13, C: 16, Elven Cloak and Boots. Frozen Solid.
17. Qonklakoo Irkling 6, Female, N, W: 15, C: 16, Staff of Withering. Turned to Stone.
18. Wheelhouse Witt FM 7, Male, L, S: 13, C: 15, Sword +2. Frozen Solid.
19. Timarina MU 7, Female, L, I: 16, C: 13, Ring of Invisibility. Turned to Glass.
20. Sticky Nobs C 8, Male, L, W: 16, C: 14, Mace +2. Morphed to Scarecrow.
21. Binblaith Elf MU 8, Female, L, I: 14, C: 13, Wand of Fear. Turned to Glass.
22. Zinzaa FM 9, Female, L, S: 16, C: 14, War Hammer +2. Gem-Prisoned.
23. Legendary Ralph MU 10, Male, L, I: 17, C: 15, Staff of Power. Time-Locked.
24. Sister Tilda C 10, Female, L, W: 16, C: 15, Staff of Striking. Frozen Solid.
And with this post I have officially surpassed my 2010 total number of posts! I can't believe I have any followers at all with just 29 posts in the past 16 months. I love you guys, man.