Homebrew Gas lamps in dungeons?

[bedir than]

Possibly relevant?
Methane pocket provided a flaming geyser near my house

Flaming Geyser State Park - Wikipedia

en.wikipedia.org

 

[Dannyalcatraz]

Also, on the asphyxiation issue, if D&D can have 45,000 different magical metals (and in 3E, a bunch of magical woods), having a magical version of coal that only has the fun parts (powering engines, making a big mess, creating gas that can go boom) without the less fun realistic parts is pretty simple. Call it lapis ignis, and we're all set.

Heck, maybe that's why the former dark lord built his castle here to begin with.

(Emphasis mine.)

I was just thinking of a steampunk dungeon using smoke & mirrors…and this provided the final piece of the puzzle for me.

The dark lord builds his fortress on or near a natural fuel & light source (“The Source”), magical or not. But the fuel source- while powerful and essentially limitless- is not easily transported. It does what it does, but mostly only where it is. So its power is harnessed by an intricate system of machines that provide power for all kinds of machine works throughout the dark lord’s keep. But smoke & soot permeates the environment as well.

But what about light?

How about a series of shutters, mirrors and lenses, focusing and reflecting light from The Source throughout the structure as well? The lenses & mirrors are adjustable by mysterious controls, themselves powered by The Source.

 

[John Dallman]

. . . the fuel source- while powerful and essentially limitless- is not easily transported. It does what it does, but mostly only where it is. So its power is harnessed by an intricate system of machines that provide power for all kinds of machine works throughout the dark lord’s keep.

There's a city which a dwarven PC of mine was responsible for re-founding. It's a bit weird because the dwarves have a lot of cultural influence although they're less than 20% of the population. One of the human groups have access to quite advanced technology, which was used to build "The Shaftworks." That's a building full of huge motors and geartrains that turns big shafts in underground utility tunnels. It's essentially torque as a utility service, like piped water.