Plasma Rifles are a common light weapon in the Covenant army, weilded primarily by Elites. It uses plasma technology instead of ammunition, neading that the user never needs to reload, but excessive use can overheat it. The plasma rifle appears in both Halo games.
The Plasma Rifle can fire approximately 300 shots of plasma. It can be duel-wielded in Halo 2, giving increased firepower. It is remarkably accurate for a rifle.
Plasma rifles are also the basis for several other weapon systems, including the plasma turrets on Wraiths and Ghosts.
The Plasma Rifle is not to be confused with the Brute Plasma Rifle, which is red instead of blue, and considerably different.