Plasma

Superheated Plasma is a primary and most common form of ammunition for the Covenant. It can burn through a Marine's ballistic armor and are equally lethal to their human counterparts. Superheated plasma is found on mostly all Covenant weapons, like Plasma Rifles, Plasma Pistols, and many others. This ammotype can be found in vehicles, namely Ghosts, on a Spectre, on Banshees, Wraiths, and many starships. They are used on turrets, as well. A Plasma Turret, Shade, and Plasma Cannons are just some of the heavy artillery using plasma.

Starship Weaponry

 * Plasma Torpedo
 * Plasma Turret
 * Plasma Charge

Vehicles

 * Seraph
 * Banshee
 * Wraith
 * Spectre
 * Phantom
 * Ghost

Weapons

 * Plasma Autocannon
 * Plasma Mortar

Explosives

 * Plasma Grenade

Firearms

 * Energy Sword
 * Plasma Rifle
 * Plasma Pistol

Turrets

 * Shade
 * Shielded Plasma Cannon
 * Plasma Cannon

Trivia

 * Plasma weapons likely work with a high temperature pilot flame and a high power electro magnet, stripping the plasma out of the flame, and projecting it forward. this trades off the extra damage of fire for the added range and lack of dependence on an atmosphere.
 * For gameplay reasons, plasma is less lethal to unshielded NPCs in the Halo games than in the novels. In the games, marines can take a barrage from a plasma weapon without being incapacitated, but in the books there are several incidences of plasma easily burning through armor and flesh.