Thief 3 is Gold.

Weren't they gonna include a customizable difficulty thingamybob?

IIRC I read somewhere(probably on the IS forums) that you could tailor the game to your needs so if you wanted to ghost through the game, you could set it so that you failed a mission as soon as you were caught, you could tick options for failing missions if you killed anyone etc...

I know they didn't include it in the final game(I've been playing it ). I was kind of hoping it would be added in the patch(which doesn't seem likely now given recent events). It would definitely have been cool to be able to do that though.