This nearly lost variant race of dwarves has skin tones ranging amongst the deep browns from nearly black to purplish. They are a proud and skilled race of warriors. They make ample use of magical items, and often know advanced techniques unknown among other cultures. Their civilization was wiped out thousands of years ago, although a few isolated pockets of individuals remain.
Dark dwarf culture embraced the theatrical and the efficient; Their storied halls were filled with ghostly torches that burned no fire, runed circles worked in precious metals that would transport them to faraway places, and hidden traps that, ready to activate via command. They often enslaved other races, especially orcs, goblins, and hobgoblins. They used extensive mental conditioning to create overseers - members of the slave race who were almost completely loyal to the dwarven culture. The overseers retained their intimate knowledge of the race, and had the ability to give rewards and built their own networks of pain and suspicion. In the midst of all of it, the slaves worked, and the dwarves practiced their dominance.
Most of their resources went into creating magical items. They perfected a technique where a certain kind of mushroom, when grown in a specific way and harvested properly, were able to capture great amounts of magical energy. They were able to channel that energy into various worked crystals and trap it there. With runes they bent the energy to their will.
They expanded slowly and reached the surface at the height of their power with over 100 practiced and extremely well equipped master warriors. They did not seek more territory, however they began to raid heavily in the area. The surface dwellers were totally unprepared for such an assault, and after a year, nearly all valuables with 100 miles of the tunnel opening were either destroyed, stolen, or hurried away in carts, carriages, and pack animals. This area included several large towns, and the steady flow of refugees quickly alerted the surface dwellers. They waged an extremely unsuccessful martial campaign against the dark dwarves, and although some did die in the fighting, it quickly became clear that the army was no competition for the masters of stealth and darkness. This began a war later known as Khilyadasin (bulgarian), or the Thousand Sons War. Many of the lands greatest warriors fought and were defeated by the dark dwarves, all within 3 years. Then as mysteriously as they had come, the dwarves disappeared.
The surface dwellers made up for their deficiencies in combat with their sheer number and their faith. They used magical eyes to retrace the path of the dark dwarves, and despite their efforts to erase their trail, one amazing clairvoyant Siyanie was able to find the center of their civilization. The surface dwelling peoples came together and began to pray to their god of light for him to find and eliminate this horrible evil from below. Many thousands gathered in the square daily to pray, and they stayed there until at last they collapsed from hunger. After a year and a day, and 30% of the population, a great white light gathered in the sky and rocketed down the hole in the earth. This divine light of judgement obliterated everything in the dwarven central cities, and even managed to track down and eliminate a large portion of the warriors not present in the home cities.
Few dark dwarves are known today, except by the very best informed.