The Underdark-dwelling drow are a key element of the Forgotten Realms Dungeons and Dragons setting in which Baldur's Gate 3 takes place. Faerun's drow exist in a highly regimented society ruled over by the noble houses of Menzoberranzan and Ched Nasad. Many of Baldur's Gate 3's drow characters come from one of these houses, and their house's history, goals, and ideologies greatly influence the character's actions and choices. Here are all the drow houses which play a role in Baldur's Gate 3.
Nightwarden Minthara Baenre starts out as a devoted servant of the Absolute. Players have a choice between killing her and helping her conquer the Emerald Grove; should they choose the latter, she becomes a party member and a potential love interest. She comes from House Baenre, one of the oldest and highest-ranking houses of Menzoberranzan.
Highly favored by the Spider-Queen Lolth, House Baenre was home to some of the most powerful magic users among the drow. Minthara was cast from her house when she rejected Lolth, but she retains the noble attitude and desire for power characteristic of her House.
House Oblodra once ranked third among the drow houses, but became seen as a threat to others due to working with and experimenting on mind flayers and other illithid creatures. Eventually, House Baenre became so threatened by Oblodra that its members wiped out the house entirely, forcing its remaining members to flee. The house's stronghold fell into the Abyss and was destroyed.
Araj Oblodra, a blood merchant met in Baldur's Gate 3, dreams of restoring her House someday. This has given her a fanatical devotion to her craft, and she believes that the potions she can craft using the player character's blood will be the key to bringing Oblodra back to prominence. She is haughty, intense, and fascinated with vampires - particularly Astarion - and willing to sacrifice anything for her experiments.
Another destroyed house, House DeVir was once ranked fourth in Menzoberranzan. They were taken out by House Do'Urden, the house of legendary Forgotten Realms hero Drizzt. According to Minthara, House DeVir are "cowards" who fell because they were unwilling to face danger directly.
Viconia DeVir, a returning character from the first two Baldur's Gate games, left the Underdark long ago when her House fell. She forsook Lolth and chose instead to serve the goddess Shar, and has risen to the role of Mother Superior of the Sharran enclave in Baldur's Gate. Because she has spent so long away from the Underdark and other drow, her behavior is arguably the least influenced by her house of Baldur's Gate 3's drow characters.
While these three drow houses play the largest role, because they are associated with party members or prominent NPCs, other noble drow houses are mentioned in Baldur's Gate 3.