Mouseferatu
Hero
They're being saved as living sacrifices to Lolth. (Or the Elder Elemental Eye, or whatever this particular group of drow worships.)
And I want to give my players free choice of race and only then tell them they've been captured by drow. (They do know they're headed for an "Underdark-themed campaign")The surprise? The game starts with the PCs as prisoners of drow. If you don't tell them that, it's less surprise and more of a "gotcha".
Besides, how does the elf player come up with these reasons if he doesn't know?
I'd tell the players how the game begins and let them come up with a reason if they want to play an elf.
On the other hand, getting your character killed off without a fair chance at retreat/surrender/negotiation is a sure-fire way to get your group disinterested in playing with you as DM ever again.This is something I couldn't ignore if I was DMing. The drow would just slaughter all of you and take anything of value. I never handwave things like this because my group would become disinterested in the campaign.
The Drow are known to take surface-dwellers as slaves.Just as a thought, what races (from either the PH or EE) WOULDN'T the drow slaughter on sight?