Drow

When the primal Elves chose to take the forms of mortals, they were one people split by conflicting loyalty to gods who reviled each other. The schism led to a conflict that ended with Lolth retreating to Demonweb Pits and her adherents exiled to The Underdark. This banishment enabled the victors to once again live in peace on Arvandor but did nothing to heal the rift.
The vanquished elves weren’t seen or heard from again for centuries. Throughout that age of residing in the darkness, absorbing the unhealthy emanations of The Underdark, subsisting on its tainted water and food, and always beseeching their god for guidance and following her poisonous dictates, Lolth’s worshipers gradually transformed into the drow: the cruel, predatory, and wicked offshoot of the elf race.

Reflections of Lolth

From the time they’re old enough to understand, drow are taught that they’re superior to all other creatures, for they remain steadfast in their devotion to Lolth despite the hardships of their existence. Any creature that isn’t a drow is useful only as a sacrifice to Lolth, as a slave, or as fodder for the giant spiders that the drow train to patrol their cities and tunnels. Among these other, lesser forms of life, the elves that live in sunlight are especially despised because they are descended from the primal elves who betrayed Lolth so long ago.
Reverence for Lolth touches every aspect of drow life. All dark elves constantly watch for signs of her favor. Any incident or physical feature can be interpreted as such a sign, and priestesses are quick to attach meanings to obscure omens that benefit their own interests.
When Lolth is well served, she rewards her faithful with favors. When she is defied, she visits the Underdark in one of her forms and takes a direct hand in punishing the malefactor in a manner that discourages anyone who might be contemplating a similar kind of disobedience, often by turning them into Driders. Perhaps making an example of malcontents in this way is simply an aspect of how Lolth’s cruel personality works. It also might be evidence of a lesson that she learned all too well from the way Corellon Larethian reacted to her betrayal of him: the smallest flame of resistance must be snuffed out before it grows into a conflagration.

Society of Blood and Poison

The principal organization in drow culture and society is the house, an extended clan that comprises many related families, plus a number of lesser families who have pledged loyalty to the house. A house’s membership also includes some (potentially very large) number of indentured drow servants and slaves of other species. A house usually specializes in a business, a service, or a craft that supports by providing income.
Houses are in constant competition with one another. They vie for money, for prestige, and, more than anything else, for power over others — the surest sign of Lolth’s approval.
No tactic is outside the rules in this ongoing conflict. Raids against another house’s outlying property (farming caverns, trade caravans, or hunting parties) are commonplace. Rumors about disloyalty, conspiracies with surface elves, or heresy against Lolth are circulated so frequently that no one knows what to be sure of. Assassinations, both by blade and by the use of special drow poisons, are a constant threat. Bodyguards and food tasters are as necessary to the survival of a high-ranking drow as air and water. Squabbles within a house also occur from time to time as relatives jockey for position. It’s a rare occurrence, though far from unknown, for drow to assassinate their own parents or siblings if that’s what it takes to create a path for advancement.

Cities without Sunlight

The drow might have not chosen to live in the Under­dark, but just the same they consider it their home, not a prison. Just as the sea elves adapted to their aquatic realm, the drow have long been accustomed to the harsh conditions of life in the Underdark. They’ve lived away from sunlight for so long that they can’t bear the touch of it on their flesh, and thus they prefer to visit the surface only at night.
Even though they live underground, drow are much more than cave-dwellers. Their cities are as magnificent as anything built by surface elves, and their defenses are even more secure. Their most important sites, like Menzoberranzan, are located inside immense, hollowed-out stalactites and stalagmites, with entrances well guarded.

Rule of Matriarchs

Females are the top figures in drow society. At the head of each house is someone who is a shrewd business operator, a skilled tactician, a high priestess of Lolth, and probably also a merciless assassin with blood on her hands. Unlike with many other races, female drow are typically taller and more robust than males.
To rise to the top echelons of power, a female must first become a priestess of Lolth. Then, to ascend to the status of high priestess, she must take advantage of powerful connections or craft special alliances. The path to ultimate power in drow society is never direct and is always paved with death.
A male drow can advance in standing as a combatant, a consort, or both. Physical beauty and fitness are highly prized in male drow, and those who are especially favored in this regard can earn protection and gifts from their matrons. A few males can attain high status in their society, especially those who serve as mages, but they never overshadow the females of their houses. Even the most intelligent, strong-willed, and devious male will never be more than a second-class citizen in any drow city or house. That situation will never change as long as Lolth reigns as their queen.