In Theif 1&2 you fail if you kill anyone on the hardest difficulty setting.
I've done all of the fallout games without killing anyone, even Fallout 3 if you don't count the one radroach it forces you to kill in the tutorial.
Arkanum can also be done without ever killing anyone.
I've done all of the fallout games without killing anyone, even Fallout 3 if you don't count the one radroach it forces you to kill in the tutorial.
Arkanum can also be done without ever killing anyone.