All short-range monsters make easy target practice for the plasma gun, but ammo should be conserved for stronger monsters such as the revenant and Hell knight. The plasma gun should be employed in short to medium range, but its accuracy makes it effective at long range as well, particularly if the enemy is large and/or not moving much.

Its primary limitation is the slow speed of the projectiles. The plasma gun has a decent damage-per-shot ratio, a good rate of fire, and perfect accuracy. Ammunition for this weapon are generally easier to locate throughout the entire game relative to rockets, ammo belts, and BFG cells, and are particularly abundant in the EnPro facility. Stray plasma bottles hold 25 units of projectile, whereas a box of 2 bottles holds double the amount. Ammunition comes in the form of plasma cells, which appear to be bulky bottles that glow a luminescent blue and possess a blue-colored tip. Similarly to BFG9000, chaingun and the newcomer machine gun, the plasma gun discards the game ammo HUD because it has its own ammunition counter in a small monitor located at the rear upper of the weapon itself. Nevertheless, it still possesses effective firepower, making it comparable to the higher-end weapons such as the chaingun and the rocket launcher. The plasma gun is slightly different from its earlier counterpart, as well as the later Doom (2016) version and the Doom Eternal version, as the projectiles now move at visibly slower speeds. 3 Series 3 Plasma gun Briefing (Video disk).

Doom 3 plasma rifle