- “The Covenant cruiser came about to face them. Its plasma turrets glowed like angry red eyes.”
The plasma turret fires magnetically contained bolts of plasma, referred to as Plasma Torpedoes, and can strike at almost any range. The torpedoes can be fired either guided or unguided, depending on the situation. Upon contact it causes severe damage to the target. The weapon can be used in conjunction with pulse laser turrets and energy projectors to decimate an entire human fleet, and can be used in ground assaults as well. Because of the sheer power of the weapon, Covenant fleets have usually won all space encounters against the UNSC Navy. The closest UNSC analog to the weapon would be Archer Missile pods, which serve the same purpose but are inferior by comparison.
The turret itself is antenna-like in appearance and is located along the sides of the ship. The beam is red or blue and short with a ball-like head. The turrets, from afar, usually appear as short spikes on the sides, the upper sides, and the bow of the vessel. The size and power of the plasma turret depends on the vessel; the plasma turrets mounted on smaller ships such as corvettes are less powerful than those on larger vessels such as battlecruisers. It also resembles the Concussion Rifle.
Before the weapon fires, it first has to charge. When the weapon charges, a ball of superheated plasma forms in front of the turret, then after about 3 seconds, it fires outward at its target. Inside the turret, gas is superheated by the ship's reactor to produce the charge of plasma. Magnetic coils shape and guide the plasma, acting as a sophisticated focusing lens. When the plasma charge impacts its target, it super heats the material which boils through shields and melts through armor.
The magnetic coils used in a MAC gun can be used to shape and guide the plasma fired by a Plasma Turret; this was seen before the Massacre at Eridanus Secundus, when the UNSC Gettysburg's magnetic coils were used to guide plasma generated by the Ascendant Justice's plasma turrets. Yet, when this happens the plasma is far denser than it would be if fired normally.
- The Covenant Remnant have several weapons known as Covenant Artillery that fire Plasma Launcher-like projectiles. It is possible that these weapons are Plasma turrets that have been removed from their ships and placed on the ground in an upright position.