Smith, on enemy A.I. in stealth games:

"Even if we weren't making a stealth game, we'd push for a stealth A.I., because it implies imperfect awareness on the part of the enemies, and that makes them a system, and they're more fun to play with then. And uncertainty is introduced into the system. That instantly means that your decisions have weight because the guys may have seen you or may not have seen you, or may have heard you break the windows, or he may not have heard you break the window."