Sometimes also called “gray dwarves,” the duergar are a subset of dwarves that dwell almost exclusively in the Underdark. Like their more well-known relatives, duergar are stocky and sport beards. Most often these beards are white, with their skin being a dull, stone gray, hence their other name.
The duergar are the result of generations of experimentation by the mind flayers. They eventually escaped mind flayer control en masse and have declared war on the illithids ever since, attempting to kill any of the creatures on sight. The experimentation by their once-captors have left the duergar imparted with the abilities to turn invisible as well as to grow to the size of an ogre for short periods of time, making them formidable foes. Due to where they live, the duergar are sensitive to sunlight. They also come into contact with the drow regularly, whom they sometimes trade with and other times make war with. A deep-seated resentment towards the other dwarvish people runs through the duergar, who assumed that they were written off by their cousins and the duergar’s animosity towards the other dwarvish peoples burns almost as brightly as does their hatred towards the mind flayers.