Yes, you can play through Thief without killing anyone
Thief just got its second unveiling last week, now retooled to be more traditional and in-line with the original games in the franchise versus the grammar grotesqueness of the announced-in-2009 Thi4f. Eidos Montreal offered further insight into Thief in a blog post, confirming that protagonist Garrett will be able to get through the entire sticky-finger adventure without taking lives.
Eidos Montreal's previous offering, Deus Ex: Human Revolution, also allowed players to make it through the game as a pacifist – save for bosses – a good example considering it too was a modern entry in a franchise that had been dormant for quite some time. Thief is currently slated to launch on PC, PS4 and "other next-gen platforms" in 2014.
[Art from the official Thief Facebook page]
