Here is one reason why we can't have friction. If you slow down when you let go of the arrow keys, the client will have to send some kind of information to the server so that other players know they are slowing down. That sounds OK, but now imagine someone hitting the arrow keys, not holding them down, either loads of packets get sent to the server, or if there is a sample rate, people will see that player begin to slow down at a different place (far enough to dodge weapons). I thought he came from SFN and brought a piece of it to MGB forums.