The drow themselves are the most numerous and politically powerful denizens of the Vault, though few are those born to the Eight Houses—most drow will be of a Lesser House, or no noble blood at all, forced to vie against their kinsmen for any status or accord.
Drow make up the largest section of the Vault’s population, but are not even a full majority. Many mirthless duergar (gray dwarves) make their homes in Yethendrin, and some svirfneblin (deep gnomes) ply their trades there, as well. By far, the most plentiful non-drow race are the bizarre derro, creatures the size of halflings who are often forced into servile slave roles, and are generally regarded as barely sane.
For centuries, the drow armies have been bolstered by summoned demons and devils—their kind are seen in the Vault, as are the tiefling children they sire on various races. Half-elves of drow parentage are not unheard of, but those that survive their difficult childhoods (often in the drow orphanages called the House of Abandonment) are likely the strongest and canniest of their ilk. Goblins, hobgoblins, kobolds, orcs, and half-orcs are represented in small numbers within the Vault, and a sizable population of surface-dwelling races (humans, halflings, dwarves, etc.) live as slaves. Some of these poor souls have been born into generations of slavery, knowing only the Vault and never having seen the fabled sun spoken of in hushed whispers.
Brutish reptilian troglodytes have found a home for themselves in the Vault, and many serve in the armies of the drow, as do the fearsome feral quaggoth, who nurture a hatred for the surface elves as strong as their drow masters. A small number of mind flayers are permitted in Yethendrin, though many drow view them with watchful distrust. Even rarer are those intelligent undead accorded citizenship in Yethendrin, though the city is plagued by no shortage of scavenging ghouls, ghosts, and other monstrosities.