Duergar

Duergar dwell in subterranean caverns far from the touch of light. They detest all races living beneath the sun, but that hatred pales beside their loathing of their surface-dwarf cousins. Dwarves and duergar once were one race, but the dwarves left the deeps for their mountain strongholds. Duergar still consider themselves the only true dwarves, and the rightful heirs of all beneath the world's surface. In appearance, duergar resemble gray-skinned dwarves, bearded but bald, with cold, lightless eyes. They favor taking captives in battle over wanton slaughter, save for surface dwarves, who are slain without hesitation. Duergar view life as ceaseless toil ended only by death. Though few can be described as anything other than vile and cruel, duergar still value honor and rarely break their word.