Plasma gun

"Plasma Rifles shoot multiple rounds of plasma energy - frying some demon butt!"

- Doom 2 Manual

The plasma gun (also known as the plasma rifle in the game manuals, help screen and code comments) is a futuristic weapon with a segmented barrel, which fires blue and white bursts of plasma. It shares the player's stock of energy cells with the BFG9000 as a source of ammo.

The plasma gun first appears in a secret area of the very first level of the second episode, E2M1: Deimos Anomaly, and happens to appear in every level of The Shores of Hell, with the exception of the Tower of Babel level. It first appears in a non-secret area in the fifth level, E2M5: Command Center. When picked up, it contains the equivalent ammo of 2 cells (totalling 40 units of energy, or 80 on the "I'm too young to die" and "Nightmare!" skill levels).

Combat characteristics
Each plasma burst inflicts 5-40 points of damage. Although the rate of continuous fire is one burst every 3 tics (about 0.086 seconds), there is a further pause of 21 tics (0.6 seconds) when the trigger is released.

Tactical analysis
Due to its high damage rate (three times that of the chaingun), the plasma gun is devastating against nearly any single opponent. A continuous barrage will stop an arachnotron in its tracks, and even reduce a baron of Hell to about half its normal movement speed and attack frequency. Attacking monsters from long ranges can be inefficient, however, as enemies tend to move too much for the bursts to be accurate; it is also difficult to use against flying monsters in open areas, as the first few hits push the enemy rapidly backward and often to one side of the stream. A good tactic to counter this weakness is to fire the Plasma Gun in bursts as in opposed to full-automatic. Otherwise, it is a very powerful weapon that can be considered the jack-of-all trades.

Although the plasma gun does not inflict blast damage, firing it in close quarters demands a certain amount of concentration owing to horizontal auto-aim, which may steer its projectiles right into a wall if the nearest monster is not directly in front of the player. For example, using the plasma gun on the cyberdemon in E4M2: Perfect Hatred, without placing the player in its line of sight, requires aiming at a point slightly to the monster's left.

Data



 * 1) This table assumes that all calls to P_Random for damage, pain chance, impact animations, backfire checks, and muzzle lighting are consecutive. In real play, this is never the case: counterattacks and AI pathfinding must be handled, and of course the map may contain additional moving monsters and other randomized phenomena (such as flickering lights). It is also assumed that all projectiles are launched at nearly the same range, so that the various procedures call P_Random in the same sequence each time. Any resulting errors are probably toward the single-shot average, as they introduce noise into the correlation between the indices of "consecutive" calls.
 * 2) Assumes that direct hits are possible, which does not occur in any stock map.

Appearance statistics
In the IWADs the plasma gun is first encountered on these maps per skill level:

The IWADs contain the following numbers of plasma guns per skill level:

Appearances in other id Software games

 * The Doom 64 plasma gun sprites are completely redrawn. It has a blue electric tube on top, which makes a constant buzzing sound. Like the shotguns, the recoiling animation is non-existent, likely to save cartridge space. It fires at a slightly slower rate.
 * The plasma gun appears as a redesigned version in Quake III Arena, another game later developed by id Software. The Quake III plasma gun has a more streamlined, futuristic look with glowing plasma visible behind transparent parts. The plasma projectiles travel at a higher velocity and create a small radius of splash damage upon impact.
 * The Doom 3 version of the plasma gun is again redesigned, with the projectiles moving at slower speed. It uses its own type of ammunition and needs to be reloaded after 50 shots.