Compared to Thief 2: the Metal Age, this (as of yet unnamed) sequel will focus more on Garrett's interaction with humans and will only display a small handful of fantastical monsters and mechanical menaces. In order to make up for the lack of beastly opponents, the AI unit has been beefed up considerably. No longer will guards circle around a room endlessly, but instead will actively search for players who have broken the silence. If that doesn't seem like a big enough challenge for veteran footpads, then you are in luck. Besides having the preset difficulty levels, players may add additional challenges to a mission. Ranging from the mild, like a preset time limit, to the Herculean, such as not being spotted or killing every guard on the premises, every gamer, no matter their skill level, will be challenged by this software.