Duergar are a subrace of dwarves, often called "gray dwarves." They have the typical stout, muscular build of their kin, but their skin is a dull gray and their hair is a darker gray or black. Both males and females are bald, but males grow long, unkempt beards. Their eyes are a sickly pale color, a result of generations living far beneath the surface. Duergar are also known for their powerful psionic abilities, which are a defining characteristic of their race. These powers allow them to become invisible and to enlarge themselves. They have no notable regional variations, as their entire race is confined to the deepest parts of the Underdark.
Duergar names are harsh and guttural, much like their language. They are typically given two names: a personal name and a clan name. The personal name is usually a single word that reflects a physical or mental trait, while the clan name is a long, complex name that signifies their clan’s history and accomplishments. This duality in their naming conventions reflects their society's blend of individualism and rigid clan structure.
Duergar were once a clan of mountain dwarves who were enslaved by the Mind Flayers. During their time in captivity, they were subjected to cruel and horrifying magical and psionic experiments. This terrible ordeal transformed them physically and mentally, turning them into a new race entirely. They are now defined by their hatred of all other races, particularly their kin, the dwarves, who they believe abandoned them. Duergar society is a twisted reflection of their captors, with a focus on cruelty, psionic dominance, and a complete lack of empathy.
Duergar society is a militaristic, slave-holding caste system where power is everything. They are masters of mining and metallurgy, and they use their enslaved races to work their mines for them. They are a deeply paranoid and distrustful people, even among themselves, and they are masters of stealth and subterfuge. They revere a pantheon of evil gods, with a powerful demon lord as their chief deity. Their religion is a grim and somber affair, with a focus on sacrifice, torture, and the domination of other races.