The Underdark is a fictional subterranean world often found in fantasy settings, particularly in the context of tabletop role-playing games such as Dungeons & Dragons. It is typically depicted as a vast network of caverns, tunnels, and underground civilizations inhabited by various creatures, most notably drow, mind flayers, and other monstrous beings.
In most portrayals, the Underdark is a place of perpetual darkness. Natural sources of light are scarce, and sunlight rarely reaches its depths. However, there are certain mechanisms through which light can be produced in the Underdark:
Bioluminescence: Many organisms in the Underdark have developed the ability to produce their own light through bioluminescence. This can take the form of glowing fungi, plants, or creatures that emit light to navigate, communicate, or attract prey.
Magical Light: Magic is often prevalent in the Underdark, and spellcasters or magical artifacts can produce light to illuminate the surroundings. Spells like Light, Continual Flame, or similar magical effects can create sources of light that are not dependent on external factors.
Crystals and Gems: Certain crystals and gems found in the Underdark possess natural luminescence. These can be used as a light source or even fashioned into lanterns or torches to provide illumination in the darkness.
Underdark Cities: Some Underdark civilizations have developed their own means of lighting their settlements. They may use magical devices, alchemical concoctions, or other methods to create artificial light sources, allowing them to see in the dark.
It's important to note that the specifics of the Underdark can vary depending on the setting or campaign being used. Different authors, game masters, or creators may introduce unique elements or variations to the concept of the Underdark in their stories or games.