Physix is the actual destructable environment inside a game. If you ever have played a game and noticed the the buildings don't get destroyed or vehicles get blowed up. The only time that some of these things happen is when they are programed into the game and they happen the same way every time and that is the extent of it they don't get any more destroyed. The actual concept of physix in a game is that these things will get destroyed and buildings will get holes shot in them randomly acording to the actions of the player. We have at this point seen some limited physix in games but as time goes by and developers implement more and more into the game it will become a lot more noticable.