[ NOTE: The information offered below is compiled from an excerpt from the Races of Renown: Plot & Poison™ book by Green Ronin Publishing®, as well as notes from The Drow of the Underdark™. Though it is not all "canon" information, the borrowed information was universal enough in nature that it blended well with the official information. ]
Slavery is second nature to the drow mindset; few dark elves can imagine life without slaves. Drow believe they have a manifest destiny as the best and strongest of all the races. It only follows that other races must serve them or become extinct.
Most drow settlements have a slave market set apart from the rest of the market district, and often just outside the settlement's limits, to keep its foul stench away from the city proper. The pits stink of death, decay, fear, blood, and offal. Drow or their servants come to the slave market to bid on the merchandise, auctioned off by the slavers who captured them.
Drow treat slaves with no respect, using and abusing them at will. To most surface slavers, a slave is a valuable trade-good, not to be damaged more than is necessary. To most drow, a slave is but a pair of hands, without limits that need be thought of; if it is killed, there are a million replacements to be had.
As such, in drow society, slaves can be killed for the smallest slight, for pleasure, or out of spite. Maiming and scarring, both physical and emotional, is another form of punishment (and amusement) commonly meted out upon slaves.
All slaves must give way to drow nobles, and are not allowed to look any drow in the eye, even those of commoner stock. Slave may only bear weapons when a drow noble allows them (usually only in gladiatorial entertainment fights, or to defend a House under attack).
Slaves encountered in drow society are usually (meaning exceptions are possible) of the goblinoid races: goblins, orcs, hobgoblins, and the like. Kobolds and jermlaine are too small, agile, and independent to make good slaves (in the mind of most drow, at least), and such creatures as trolls and giants are too large and powerful. Drow only enslave other drow captured in battle, particularly debtors and noble drow whose families do not pay ransoms for their return. As some societies may have different viewpoints on this matter, that fact may vary slightly from place to place. Some drow communities don't enslave drow at all, sacrificing or merely killing captives and dangerous criminals.
Drow slavers rigorously test their stock for tractability and aptitude before they put the creatures up for sale. More capable and stronger slaves have a higher starting bid. Troublesome slaves are tortured and abused until they become obedient or die.
Below is a list of some of the more common slave creatures, as well as a variety of more uncommon ones, with brief notes on how such creatures fit into their roles.
Athach
Athachs are powerful creatures, far stronger than most of the drow they serve as slaves. The dimwitted monsters have little sense of self and become quite docile after sufficient threats and applications of pain. Since they speak only Giant, a foreign tongue to most dark elves, they are useful mostly as fodder for gladiatorial combat and as laborers on projects that require a great deal of muscle but little explanation or thought. Most athach slaves are used for mining and quarrying.
Bugbears
Bugbears are strong and hardy creatures who generally enjoy working as guardians and enforcers for their drow masters. Drow often put bugbears in a position of authority over other slaves, allowing them to feel superior while keeping them under control. When put to other work, bugbears become surly and difficult. Drow who wish to keep bugbear slaves usually learn Goblin or Common tongues.
Choker
Chokers are stupid, nasty little predators native to the Underdark. Dark elves use them the way surface dwellers use guard dogs. Slavers often patrol their stockyards with two or three leashed and collared chokers walking ahead of them to help subdue unruly slaves. Capable of speaking and understanding Undercommon, chokers are easy for drow to train.
Drow
With few exceptions, drow only enslave other drow captured in battle, particularly debtors and noble drow whose families do not pay ransoms for their return. Some drow communities don't enslave drow at all, sacrificing or merely killing captives and dangerous criminals. Other communities keep drow as slaves in all but name.
Duergar
Duergar can make for troublesome slaves. With a darkvision range nearly as great as drow have, a strong resistance to controlling magic, and a knowledge of the Underdark, they can be a threat to a drow community if too many of them remain together.
Despite this, some drow communities make good use of the superior smithing skills that their Duergar captives possess.
Dwarves (Gold or Shield)
These make surprisingly good slaves. Despite the dwarven reputation for stubbornness and will, most gold and shield dwarves quickly lose hope and interest in fighting once plunged deep into the deadly web of a drow settlement. Surrounded by enemies on all sides, some choose to go down fighting; these dwarves never make it to the auction block. Since many speak Undercommon, and they all possess the Stonecunning ability, they are easy to train for many tasks but are especially useufl for the difficult and complicated task of stonemasonry.
Elves
Drow do not often take other breeds of elves as slaves. Surface elves are usually killed on sight when discovered roaming the Underdark, and elves captured from the surface are usually made into sacrificial offerings. Sometimes drow will keep elves alive for a time to provide a suitably important sacrifice for a high holy day or as a special exhibition of torture. Such prisoners often wish they were dead soon after being captured.
Ettin
Nearly as strong as athachs, ettins are nonetheless much less desirable. An ettin's master can use the Orc, Goblin, and Giant languages to communicate with it but must know all three to get the idea across with any efficiency. Most ettins act as guards and are taught the same simple commands one would use to control a dog.
Goblins
Goblins are weak, making them useless in the eyes of many drow. Some drow keep goblin slaves only as amusement, though many of the more menial and debasing tasks can be doled out to goblin slaves.
Gnomes
Most gnome slaves are rock gnomes. Svirfneblin are generally hated and killed on sight. Few forest gnomes find their way so far beneath the surface, and even fewer drow raiding parties happen upon the reclusive subrace's settlements. It matters little to the drow, as most can't (or don't care to) distinguish any difference between rock and forest gnomes. As rock and forest gnomes lack darkvision, they're easily controlled by denying them the ability to see, but they are often weak laborers.
Drow employ gnomes with gemcutting skills as jewelry makers and gem miners, but most others are bought for torture and sacrifice. Fortunately for trainers, many gnomes speak either Common or Goblin in addition to their own language.
Grimlock
Slave keepers themselves, grimlocks know their place when taken captive. So long as they are kept well fed, grimlocks make excellent guards of other slaves and shock troops for drow war parties. Their ability to "see" in drow Darkness makes them especially useful in wars and skirmishes between Houses.
Halflings
Surface halflings are less useful than gnomes for most tasks, but they are preferred for work where dextrous hands and small size are an advantage. Halfling slaves often labor as weavers and leatherworkers. Like humans and surface gnomes, they are easily controlled by witholding light. A slave master must know Common to train halflings; learning the Halfling tongue is considered a ridiculous waste of time and effort. Most halflings that do not speak Common are killed or sold to temples for sacrifice.
Hobgoblins
Hobgoblins are naturally organized and martially minded, making them valuable as guards, gladiators, and regiments in House armies. Unfortunately, hobgoblin captives tend to seek one another out and plan escapes or plot revenge. Thus, drow prefer to gain hobgoblin slaves through intimidation, forcing hobgoblin tribes to pay living tribute. Hobgoblins forced to swear fealty to the drow often become their most loyal servants.
Humans
Drow think of humans as little better than beasts, though they consider humans as dangerous beasts, unless the subject in question has no fighting or magical ability. Human slaves are useful for many tasks and can learn many complicated skills quickly, often regardless of language barriers. Especially quick studies with strong limbs and dextrous hands are highly prized.
Human slaves often prove to be the easiest to control, as well. Despair crushes their independent spirits, and their natural survival instincts and adaptability oft times lead them to keep their heads down and simply hope for the best.
Kobolds
Weak and frail, kobolds are next to worthless as slaves. Their small stature, natural agility, and fiercely independent spirits don't help matters. As such, those drow who do invest in kobold slaves usually only do so as amusements for torture and abuse. Master torturers often keep a few kobolds around as cheap teaching aids.
Ogres
Ogres make good slaves for simple jobs, like hauling mined stone, and for tasks that suit their bloodthirsty natures. Many drow take pleasure in subduing ogres' violent and chaotic tendencies to turn them into submissive and servile toadies. Drow who wish to master ogres should learn to speak Giant.
Orcs
Drow view orcs the way humans view wild dogs--they're useful only with proper training. Training orcs, however, can be a difficult process. They learn slowly, lazily take to tasks unless constantly threatened, and are prone to pointless acts of rebellion. Even so, orcs are strong; a drow who can't afford an ogre often makes due with one of these.
Minotaurs
While not quite as strong as an ogre, minotaurs prove just as troublesome to train, and are even more cunning. Despite this fact, some drow go out of their way to break down a minotaur and enslave it, though the practice is uncommon, as the process itself is costly, and they are far more likely to be able to escape than an ogre of comparable relative usefulness.
Skum
A slave race created by aboleths, skum would make excellent servants were it not for their devotion to their creators. Skum traded to drow by aboleths are useful and faithful, but their highest loyalty is always to their aboleth lords. Add to this the fact that skum speak only Aquan, and they make for difficult slaves despite their natural tendency to do as a master asks.
