Within the molten crags of volcanos, Duergar, also known as grey dwarves, carve their cities. While this location poses a threat to their establishments, the flow of lava to their forges makes it all worthwhile. There are some duergar that live upon the surface, though these are criminal outcasts. Marked by tattoos, these exiles bear their shame wherever they may go.
In some ways, duergar are better adapted to underground living than most dwarves. These dwarves can see into the pitch black of darkness, a bit beyond what darkvision does allow. Within the depths below lurk monsters with great powers of manipulation. Due to generations of fighting these creatures, duergar have become resistant, though not immune, to their techniques: paralysis, phantasms, poisons, and some types of illusion. Living near volcanoes has also built up their tolerance to scorching heat.
Duergar are similar in size, though are vastly different than those of their kind. They tend to be thinner than other dwarves. Their skin and eyes range from black to grey. Most duergar, both males and females, prefer to be bald. Only males grow beards, which are white in color. Few duergar grow quills upon their scalp and face. By command, these quills may be fired in offense.
Like other dwarves, duergar hold a long tradition of crafting. They are fine craftsmen with an eye for detail, though their designs are pragmatic and not at all ostentatious. Fanciful things of unique patterns, glittering ore, and gems are deemed wasteful, and could easily give away their presence to predators. They are not, however, a people that completely lack a sense of art. Scenes of warfare, cruelty, and venerations of blood adorn the walls of their clan halls.
Duergarr are a grim, pessimistic, cruel, and malevolent people. At an early age, they are taught only the strongest, most cunning survive; and all others among them will show no mercy if standing in the way of their goals. When it comes to the motives of others, they are highly skeptical. Duergar do not look upon other members of their race and clan as kin, but as adversaries. Toward mountain dwarves, duergar hold a particular hostility, and blame them for their troubles with underground monsters.