At one point I came across a shady character who I knew was up to no good, so rather than just accepting what he had done I snuck through a ventilation duct and hit him and his buddies with a biotox dart rendering them both unconscious and me free to rummage around in my surroundings. The entire game is like this since you can play through without firing a single shot using cloaking and thermal masking mods to become invisible to humans and all machines.