Heavy weapon dude

The Chaingunner (sometimes called a Chaingun guy, Heavy weapon dude, or occasionally just Dude) is a marine who has been turned into a zombie during the demonic takeover of Earth. He appears as a burly, dark-skinned man with a shaved head and a goatee, wearing red body armor and carrying a chaingun and a bullet belt.

The Doom instruction manual says:
 * Geeze, weren't shotgun zombies bad enough? At least when you fade these jerks you get a cool chaingun.

In the instruction manual the chaingunner is called a Former Commando.

The chaingunner is first encountered on MAP03: The Gantlet (Hurt me plenty, Ultra-Violence, and Nightmare!) or MAP04: The Focus (I'm too young to die and Hey, not too rough).

Combat characteristics
The chaingunner attacks by firing his chaingun, which does slightly less damage per bullet than the player's chaingun and whose rate of fire is also somewhat lower. Once he begins to fire, however, he holds down the trigger until his target dies or leaves his line of sight, or he is stunned (causing him to move) or killed. When slain, he drops the chaingun, which contains 10 bullets (20 on I'm too young to die and Nightmare!).

Tactical analysis
Because the chaingunner employs ranged attacks in rapid succession which cannot be dodged (even the Spider Mastermind pauses briefly in her tracks before firing, giving the player a fraction of a second to take cover), the player must avoid spending any time at their short or medium range if he possibly can. One shot from the super shotgun at close range almost always kills a chaingunner, continuous fire from the chaingun at close range almost always prevents him from firing, chaingun "tapping" normally limits him to a couple of bullets during the remainder of his life, and a single shotgun round at point-blank range is usually non-fatal and leaves the player suddenly vulnerable while reloading. Due to their profligate use of ammunition, multiple chaingunners at any distance may well reduce the player's health by 100 or more points in the time it takes to cross a large room; in that situation, it is essential to remain in motion and to take advantage of nonlinear weapon behavior (the circular scatter of SSG pellets, vertical blast damage done by rockets, optimizing one's angle of elevation by chaingun tapping, etc.) at every opportunity.

The chaingunner's high rate of fire makes him a formidable presence in monster-monster battles; provided he survives the initial blow, one chaingunner can actually take down a healthy Cacodemon (often), Revenant (perhaps), or Hell Knight (from time to time). Like the player, the chaingunner must live with a certain amount of recoil after the first few bullets, which means that a group of them in company will cheerfully hammer each other to pieces given sufficient time and maneuvering space &mdash; for instance, the ten chaingunners of MAP21: Nirvana are easily reduced to three by taking repeated cover behind the blue wall to the west.

The weapon and item distribution in DOOM2.WAD, and megawads which would imitate it, seems most balanced at skill level 3. Playing on Ultra-Violence tends to insert additional chaingunners on the early levels, which sometimes gives the player a chaingun about 20 minutes before it would really be fair.

Appearance statistics
The IWADs contain the following numbers of chaingunners: