Directly from the blog of Eidos we present some interesting extracts from an interview with Nicolas Cantin, director of game Thief . In the interview Cantin focuses primarily on Focus , that innate ability of the protagonist that allows him to focus and then prevail on certain enemies thanks to improved response times or to find useful items to its purpose. In this sense Cantin pointed out how the same Focus can be turned off, and then enable the "purists" to enjoy the title without any help whatsoever. Here are some excerpts of the interview.

the Focus is something you'll have to manage, you need to accumulate. The player may choose which one is the right time to use it, given the various methods of use. Only the player will decide how and when to use the Focus in the game.

The Focus however is not required and no one will be forced to use it, as purists may then decide to disable it and manage so your style of play.