During Halo 3 and Halo: Reach, when firing the Rocket launcher, if you cause an explosion to go off next to the midair rocket, the rocket will not continue to go in a straight line towards its intended target, but spirals into a path opposite the explosions. This can be done using any explosion, such as Fusion coils, but works best with Frag Grenades, plasma grenades or with a Gravity Hammer. The latter is used by some players to play "rocketbaseball," where the Hammer is the "bat" and the rocket is the "baseball."