Rampage is a weapon that sends several projectiles that travels in wide-reaching sine waves from the player's position to the opposite end of the screen, dealing 15 damage per hit. It completely ignores the player's currently set power and only uses angle to determine which side travel towards. Any enemy that the projectiles run into will be hit, although the projectiles will stop "rampaging" after a while, dealing damage to any tanks they hit. However, Rampage and Riot will never hit any ally while they are still traveling.
It is possible to concentrate most of the Rampage/Riot's damage by being close to an enemy while using it. Getting too close can cause you to hit yourself but if done properly you can ensure 60+ damage on a single target using Riot.