This trick can only be done online and as long as you aren't the host. Take out your pistol (recommended) or another weapon besides a Lancer and take cover over something you can jump over. Hold the Right Analog-stick so that the camera is over your head, then release it while holding the Left Analog-stick Up. While still holding Left Analog-stick Up, quickly move it Down and press A and the same time. Your character should look as if he is hovering and walking backwards. Keep holding the Left Analog-stick Down, then press A + B. This cannot be done too fast or slow; the timing must be perfect. Your character should flip up in the air. Note: The best place is to try it in is Gridlock, at the side near where the river is are three ledges. Try the trick on the last ledge closer to where you spawn on the western side.