This is quite simply the best action titles I have ever had the pleasure of experiencing. In fact it ranks as one of my top three favorite games.  So what makes this game so great?  Every aspect of this game lives up to its original premise (and title). You ARE a thief. This is definitely not  your average first-person blast-fest.  In fact, the best course of action  is to avoid combat at all costs.  Stealth, concealment, quietness, and  thinking are what counts here.  The enemy artificial intelligence is some  of the best I have seen.  Enemies will here you if you make too much noise,  see you if too much light shines on your hiding place, call for help, and  generally behave like living and breathing people. Plus, the later enemies  are some of the scariest I've seen.  The story is superb, the weapon  selection perfect (love the black-jack), and the atmosphere extremely well  fleshed out.  The cutscenes are some of the best in gaming and the  voice-acting is top-notch.  To summarize, this is one of the best action  titles to ever come down the pipe. No gamer should miss it.