Homebrew Gas lamps in dungeons?

[Whizbang Dustyboots]

Working backwards from the needs of running a planned in-store Shadowdark campaign -- I want to give groups a total of two torches for a three-hour game, so that everyone is motivated to get back to town before the end of our allotted time -- I realized I didn't want humanoids in the dungeons to have torches for the player characters to grab nor the villagers the PCs bunk down with to have them or oil lamps either.

Which made me think about gas lamps, both in town and in the dungeon (which is below the former lord's ruined castle). There could be lighting the humanoids (and PCs) could turn up or light as needed, while still preventing the players from carrying that light into dark areas (where the lighting system is damaged).

Looking at how gas lights worked, it looks like I'd probably want this to be working off of gas derived from coal.

Beyond the danger of things possibly going BOOM in the dungeon (a feature, not a bug for me as GM), what other implications of this am I missing? Are there any show-stopping problems? Any cool opportunities? And assuming that somewhere in the dungeon is a massive pile of coal, what would the gasworks itself look like? Could skeletons run it?

 

[sevenbastard]

Honestly I thought this was going to be about lying to your players to make them feel crazy. Probably something about room size and such as they try to map.

 

[Whizbang Dustyboots]

Honestly I thought this was going to be about lying to your players to make them feel crazy. Probably something about room size and such as they try to map.

Oh, there will be false hydras as far as the eye can see.

 

[Umbran]

Beyond the danger of things possibly going BOOM in the dungeon (a feature, not a bug for me as GM), what other implications of this am I missing?

Yes. Oh, yes...

Are there any show-stopping problems? Any cool opportunities?

Both.

You ever heard the old cliché of a suicidal person sticking their head in the oven to kill themselves? That isn't based on modern natural gas. That's based on coal gas - coal gas is composed of a mixture of methane, hydrogen (cool, both of those burn), water, carbon dioxide, and carbon monoxide.

So, in any chamber lit by coal gas, heck, any entire dungeon lit by coal gas, what you do is snuff the flame, but leave the gas running, and let the carbon monoxide do the work. Which really means that it is incredibly stupid stuff to use to light any space with poor ventilation. At least, if you are living. For undead, it might be ideal. I'll have to remember that...

How many windows does your dungeon have?

And assuming that somewhere in the dungeon is a massive pile of coal, what would the gasworks itself look like? Could skeletons run it?

Original coal gasification was done by heating coal to a high temperature, in the presence of steam and oxygen, under high pressure, and tapping off the resulting gases. The basic chemical reaction is 3C (i.e., coal) + O2 + H2O → H2 + 3CO. The mixture of H2 and CO is often called "syngas". You can imagine a big space filled with large reactor vessels being heated, with pipes and pressure gauges and valves everywhere. Your party artificer should faint with pleasure at the sight of it.

Skeletons with an Int of 6 could tote coal around, follow orders and such, but would not be suitable to monitor a high pressure and temperature process and not have it explode. Skeletons led by a more intelligent undead engineer? That might work.

Of course, that facility, and the carbon monoxide it produces, are a risk to every living thing in that dungeon.

Death, explosions, what's not to love?

 

[Whizbang Dustyboots]

How many windows does your dungeon have?

The plan for this was to -- other than the lack of torches and oil lamps -- lean into tropes as much as possible. So this is a classic skull mountain set-up, with the nose and eye sockets being giant caves in a sheer cliff and entry to the dungeon being through the "crown" of obsidian spires on the top of the mountain.

So at least portions of the mega-dungeon would have ventilation and if you're a dark lord with lots of goblin and orc soldiers -- because that's who tropey dark lords hire -- setting up some sort of ventilation system would be doable.

 

[aramis erak]

Beyond the danger of things possibly going BOOM in the dungeon (a feature, not a bug for me as GM), what other implications of this am I missing? Are there any show-stopping problems? Any cool opportunities? And assuming that somewhere in the dungeon is a massive pile of coal, what would the gasworks itself look like? Could skeletons run it?

In dungeons, you have carbon dioxide and carbon monoxide buildup - Towns can use gas lamps because the gas dissapates into the atmosphere.

Dungeons are notoriously low airflow... well, except many of my homebrewed ones, where I do actively consider airflow.

So, CO and CO2 buildup, Oxygen displacement by methane/ethane... "Boom" is the least interesting (and likely) result - simply because the stoichiometry is wrong more often than not.

 

[Deset Gled]

The presence of a gas system is just too modern and industrial for my taste in a fantasy setting. But even if it existed, it seems like a particularly ill-advised method of lighting a dungeon. If I knew it existed as a PC, I would absolutely be trying to use the gas to kill any monsters or BBEGs inside.

My personal solution to similar problems is bioluminescent fungus. My players have grown used to glowing goop that commonly appears in dark areas. It's easy to have it grow wherever needed and be as bright or as dark as desired. And you can either allow it to be collected and used as a dim makeshift light source, or have it wither and die quickly if characters try to move it. It's a simple handwave that I've gotten a lot of mileage out of.

 

[Fenris-77]

The dungeon in Ave Nox has pipes and gas built into it pretty much exactly like this and it's framed both as lighting and constant hazard. It's cool.

 

[Dannyalcatraz]

The presence of a gas system is just too modern and industrial for my taste in a fantasy setting.

IRL, the Murdoch coal gas lamps were invented in 1792, so I’m kinda with you there for “classic” fantasy settings.

 

[Whizbang Dustyboots]

My personal solution to similar problems is bioluminescent fungus. My players have grown used to glowing goop that commonly appears in dark areas. It's easy to have it grow wherever needed and be as bright or as dark as desired. And you can either allow it to be collected and used as a dim makeshift light source, or have it wither and die quickly if characters try to move it. It's a simple handwave that I've gotten a lot of mileage out of.

I spent too many years with the D series Underdark. While the fungus can be cool, I'm kind of over it.

And its extremely dumb implementation in BG3 -- "look, you can see perfectly in all areas of the Underdark!" -- was really the nail in the coffin for me.

For this, I want to lean into the Saruman vibes from the LotR movies and turn the dial all the way to the beginning of steampunk and have his fortress and the nearby town perpetually stained with soot, etc. The actual main machinery of war will have been destroyed by the forces of good before the game begins, but in the ruins, there will be bits and pieces of what came before.