Drow
Black-skinned and white-haired subterranean elves who are allergic to sunlight. They produce adamantine equipment(Which falls apart in sunlight, yet is bad-ass underground), take slaves, are ruled by a matriarchy, have magic resistance and hate normal elves.
90% of all player character Drow will be Chaotic Good and be Rebelling Against The Evils Of Their Race, thanks to the raging hard-on underages have on Drizzt.
Unified Setting Description
Drow are a northern race, possibly related to the elves in distant ancestry. This doesn't concern them in the least as they are busy building a collection of city-states filled with uber-competitive individuals.
Drow assassins are considered the best in the world. This is true. The reason is that Drow prefer to crush their rivals politically, economically, stylistically or legally. (Drow lawyers are considered the second-best in the world. Debate rages over the #1 slot.)
To use an assassin is an admission of failure, which is why such hits are always untraceable. For a rival to be linked to the actual death of an enemy would be a fashion and legal disaster. Hence Drow assassins are masters of seemingly accidental and natural-causes deaths.