Tower of Power is the most common nickname for a gametype created mainly for the Halo 2 map Ascension. The game is played with two teams, and the object is to control the tower with the .50-caliber turret mounted atop. The turret itself is located on the large, multi-level Tower. Everyone starts out with close range weapons, usually a Shotgun. There is no motion sensor or shields. This gametype can also be played on Lockout with the turret located on either the Sniper or Battle rifle tower.
Usually, since the front of the tower is guarded by the turret, most smart players would take a "back door" using a path with the entrance near the Banshee spawn pad.
The original creator was Stew Stevenson (ShieldsE9) in 2005. The original had Plasma Pistols, Shotguns and a Banshee, but later adapted to just Shotguns.