Ok, now, this is how to turn mouse acceleration off. It will take you a while to get used to it, but in my case it raised the usual accuracy rate in insta modes significantly once I got used to it. If you run a yard, it will always be a yard that you have to run, no matter how fast you do it. This is way more natural, as your body is used to this in real life. E.g.: if you move the mouse one inch it moves 200pixels on the screen, no matter how fast you perform the movement. Without acceleration, your mouse pointer on the screen moves in a set ratio. What's bad about this is that your body can only guess (approximately) how far a movement in a certain amount of time moves the mouse on the screen, but it's just a "feeling" and no matter how good you will get at it, it stays half as good as it could be if there was no accelleration. And if you move the mouse the 4 inches in a quater of a second the distance will be 800 pixels on the screen. If you move the mouse the same 4 inches in half a second it moves 400 pixels on your screen. As an example with imaginary values: you move your mouse for exactly 4 inches in 1 second, then the mouse arrow on the screen moves 200 pixels. What mouse acceleration does is it moves you mouse arrow on the screen further the faster you physically move your mouse on your desk. This is something for the Mac users out there: When you play Cube2/Sauerbraten on OS X you are handicapped compared to others (= linux and windoze users)! The problem is called "mouse acceleration" and it's turned on in OSX and different from win and linux, there is no setting in OS X to change that.