Duergar

Folkloric origin: In local English vernacular the Simonside Dwarfs (also called Brownmen, Bogles and Duergar) are a named small race associated with the Simonside Hills in Northumberland; the brief sources record them as place‑bound hill folk with a named leader, Heslop, but give no extended premodern origin narrative in the provided excerpts. RPG origin: The modern fantasy duergar are a constructed subterranean dwarf people developed for tabletop role‑playing campaigns; canonical entries in game SRDs, legacy RPG texts and campaign setting material place them as an underworld variant of dwarves occupying deep caverns or the Underdark and, in some lines of lore (e.g., Greyhawk), as a people sometimes corrupted by infernal influence (hybrids such as durzagons are recorded in Greyhawk material).

Folklore: The supplied folk excerpt identifies them only as a 'race of dwarfs' tied to the Simonside Hills and does not furnish a physical description beyond dwarf‑status. RPG tradition: Game texts consistently depict duergar as dwarflike humanoids adapted to darkness — examples include long beards and baldness in some depictions, dull gray skin and low, heavy brows, and eyes that absorb light; 5E SRD and other system entries present them as Medium humanoid (dwarf) with features appropriate to dwarves. Greyhawk‑specific variants include infernal hybrids (durzagons) with rust‑colored skin, sharp claws and venomous beards and descendant maeluths described as resembling dwarves but with red eyes.

Folklore: The Simonside excerpt supplies no particular supernatural abilities or behaviors beyond their local identity and a named leader. RPG tradition: Duergar are mechanically defined with subterranean adaptations — for example, 5E SRD entries list darkvision (e.g., 120 ft. in some system texts) and resistances such as poison damage resistance; they are depicted in game lore as culturally hostile or antagonistic toward surface dwellers and as a risk within deep‑cavern campaign environments. Abilities and statistics vary by game system and edition; some campaign lore also records infernal crossbreeding (Greyhawk durzagons) that alters physiology and grants additional monstrous traits.