D&D General Is it dark in your underdark adventures?

My semi-derived from Out of the Abyss campaign had the "faerzress", residue of ancient Elven High Magic, giving a soft glow to the tops of all the great caverns of the Underdark. Having actual darkness is awesome for when players are exploring particular locations where I have an interesting idea for how to use darkness, but just having it be dark for days on end of travel wasn't my jam and would sacrifice a lot of spectacular scenery for some fussy immersion and general spookiness.

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Getting lost in fantasy maps

I am using Downcrawl to develop my underground, after years and years of dissatisfaction with TSR/WOTC’s Underdark, finding Downcrawl was a revitalizing for me.

Downcrawl has large caves filled with a nearly ever present phosphorescent fungus that can also function as an orientation system. Smaller or distant caves can be utter dark.


I have no problem with darkvision in lots of races, but... penalties must be enforced and maybe broaden for not having a light source.

So outside attack rolls, everything remotely depending on sight should be at disadvantage:

Perception as normal, Investigation, Insight, Survival, using most if not all tools, Medicine(you cant see clearly to stop bleeding or similar), Sleight of hands,

Because of mentioned above, except warlocks or other special darkvision cases, most underdark is illuminated where there is some work doing.

Underdark races might even cultivate glowing fungi so the can have cheap and reliable light source. Continual flame is very important commodity.


From my manual "A dungeon is a recipe made of humidity, stench, stale air, dirt, mud, remains of creatures, traps, treasures, traps (abound ...), monsters, enemies, monsters (abound!), Darkness, sinister noises, mushrooms , creaks, yelps, screams, moans .. but also of fear, tension, thrill, terror, horror,ecstasy, pain, disappointment, joy and treasures!"
and yes, my dungeon are very dark..



My version of the underdark is actually a different realm altogether, Svartleheim. It can be reached from portals and connections deep underground, but it is suffused with dark radiation*. In many places there are phosphorescent mosses that convert the radiation into dim light which those who dwell underground spread wherever they can.

There are large caverns with enough of this moss that plants and even crops can grow, the area is about as bright as daytime with heavy clouds. I did this because it never made sense to me that you had all these predatory creatures running around - what are they eating? If you have herbivores or creatures lower on the food chain, how many can survive just eating moss and mushrooms?

*Drow and svirfeneblin have gray skin because of the radiation.


First Post
Keep in mind when the underdark was conceptualized the inhabitants had infravision not dark vision this was changed in third Ed so originally it was pitch black pretty much everywhere even the cities aside from certain areas ultimately this had to be changed with the infravision change so now it's generally pictured as fairly well lit from a number of different sources.

James Gasik

Pandion Knight
Even with infravision though, you don't have perfect sight of all things if you go by the "seeing heat" interpretation. Though I do recall Drow having special lanterns that provided light only if you had infravision, and in Menzoberranzan, mages light up a tower with fireballs to provide a clock of sorts where you can tell time by how warm it is.


I love using darkness it my game as I use a virtual tabletop - Roll20. It works really well for taking lighting sources, darkvision etc into account and it makes light a very important consideration. I tend to forget to give disadvantage in dim light though.


Victoria Rules
If someone has a torch up, do you force them to figure out if they are still going to hold the torch during a fight?
Most of the time I assume the torch or lantern has been put down, unless someone wants to use it as a weapon (I've seen this happen now and then), but is still alight.


Most areas are pretty dark (glowing mushrooms, etc) to pitch black, so you need a light source (no fan of darkvision… it is more limited than in the PHB), some have plenty of light (lava flows, settlements, …)
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I see this is a bit of a thread necro, but just the same, I tend to picture the Underdark in the same way WotC does:

Underdark Fungus Grove (1).jpg

Underdark Fungus Grove (2).jpg

Underdark Outpost (1).jpg

Underdark Outpost (2).jpg

Tony Vargas

One solid black square as an illo in an underdark section might've been fun, like the blank illo of an Invisible Stalker, but let's have some art, and artists need light....

My Underdark is not just mostly pitch dark, but also a mysterious, dangerous, "alien" place to a surface human.

Most of the Underdark is dark. A deep natural dark. Also with plenty of supernatural and magical darkness effects.

There are plenty of natural glowing materials, and bio luminescence of both plants(and such) and animals. Though they are a bit rare and scattered.....but most of all dangerous and deadly. Light in the Underdark is is a lure for all sorts of creatures and other things for traps or worse.

Nearly every intelligent creature and more so societies use both light and darkness for all sorts of effects. Drow places really stand out with 'spooky' lights and colors.

As an Old School gamer I come down hard on light being used underground, and the Underdark. Characters need to keep track of things that create light, just like any other resource. Character's foolish enough to carry a bright light paint a massive target on themselves.

Few places in my game world have claimed more character deaths.


Goblin Queen (She/Her/Hers)
From my manual "A dungeon is a recipe made of humidity, stench, stale air, dirt, mud, remains of creatures, traps, treasures, traps (abound ...), monsters, enemies, monsters (abound!), Darkness, sinister noises, mushrooms , creaks, yelps, screams, moans .. but also of fear, tension, thrill, terror, horror,ecstasy, pain, disappointment, joy and treasures!"
and yes, my dungeon are very dark..

I think you forgot traps. And monsters. And traps.


Not necessary just talking about Forgotten realms.

Are there any light sources in "general" for the regions not otherwise lit by torches/lanters

My Underdark is a bit different. There are two different situations - one constantly dimly lit and the other periodically lit, but mostly unlit.

When you go down from the surface of my world and enter the Underdark there is a roughly 50 mile deep layer that is riddled with passages, caves and chambers. It can take weeks to 'hike' down to the 'bottom' of this layer, or it can take 25 minutes to "skydive" where there have been straight chute tunnels made.

At the bottom of this layer gravity flips. As in Spelljammer, there is a flat (really a huge sphere) line where two gravity forces come together and effectively create zero gravity (although you can toss a stone and watch it alternate between gravity fields) - but much of this area is massively flooded to a depth of several miles. Once you 'flip' over you will find yourself in another world of passages, caves and chambers that requires another 50 mile climb up towards the center of the world ... before you reach the Underdark Surface.

The Underdark Surface is a Dyson Sphere like setting surrounding a purple 'star' that emits dim purple light. Essentially, it is perpetually like it is 20 minutes after sunset and you're wearing purple lensed sunglasses in the Underdark surface. That world is truly massive, but has very limited plantlife and ground based water - resulting in much of it being inhabitable only to things that do not need to eat or drink. There are, however, some settlements in oases where there is a water source, and some creatures have been able to adapt to pulling their water from the air (as it is a cold and humid wasteland).

The passages, chambers and tunnels are speckled with naturally occuring bio luminescence, magical lighting, and other sources of natural light (lava streaks, etc...) - and unnatrual light (fire elementals). There are many civilizations in the larger chambers - and whether their massive chambers are lit or not is a matter of survival strategy, generally.

The most common non-teleportation travel into the Underdark surface in my world is to fall the 50 miles to the 'bottom', then use flight magic to climb up the 50 miles to the Underdark Surface. There are also a few 'Elevators' that can take you all the way, although they are hard to maintain. These areas tend to be extremely well lit to aid in their maintanence and defense.
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Since someone else included an image of the underdark, I thought I'd include a picture of what I envision the underdark looking like. In a spoiler for those that don't want to see such a disturbing image

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