Imp

Introduced in Doom (1993), the imp is a recurring enemy that attacks with fireballs from a distance and claw swipes at close range. Its appearances across Doom and Doom II make it a familiar part of the series’ demon roster, with variations in placement and combat conditions shaping how players encounter it.

Design and appearance

The imp is a bipedal, humanoid creature with red eyes and brown, leathery skin covered in bony spines. In the original Doom source code, it is identified by the object name MT_TROOP, and the sprite name TROO.

Combat behavior

The imp has two attack modes depending on proximity to its target. At range, it rears back and hurls a bright red fireball that deals 3–24 points of damage on contact. Unlike hitscan attacks from armed zombie enemies, the fireball can be dodged by strafing, which makes the imp’s ranged threat manageable once players learn to keep moving. At close quarters, if the player steps within melee range, the imp swipes with its claws instead, dealing 3–24 points of damage.

The imp is not a passive entity. Once it detects the player — through line of sight, audible noise, or damage — it enters an active pursuit state and will navigate around obstacles and follow the player through corridors. Firing a weapon can alert nearby monsters that hear it, potentially turning a single-imp encounter into a fight with several enemies. These monsters are not alerted by other monsters merely making noise.

Role across the Doom canon

The imp appears in Doom, Doom II: Hell on Earth, Final Doom, and many community-made WADs that target compatibility with the original game engine.

In Doom II, the imp appears alongside new monsters such as the hell knight and revenant. The imp continues to appear in Doom II maps, often alongside more specialized enemies such as the arch-vile or pain elemental.

The imp is just one of the many enemies players encounter throughout the series, each with distinct attacks and combat behaviors.

For an overview of other threats, see the Doom enemies guide. Choosing the right weapon for each encounter is equally important; the Doom weapons guide covers the arsenal available to fight these monsters.

Internal and technical details

Within the game’s internal data structures, the imp is identified by the thing type number 3001. It has 60 hit points. The imp’s fireball projectile deals 3–24 points of damage (calculated as ((random % 8) + 1) × 3, or 1d8 × 3), the same range as its melee attack. These values are hardcoded in the original Doom executable and are preserved in vanilla-compatible source ports.

The imp’s pain chance — the probability that a damage hit will interrupt its current action and play a pain animation — is set at 200 out of 256 (78.1%). This gives it a relatively high chance of entering its pain state when hit.

The imp drops no items on death. Its corpse uses a flat, splayed sprite and can be gibbed by excess damage from high-powered weapons such as the rocket launcher or BFG9000.

Nightmare! and the -fast parameter

On Nightmare!, monsters can respawn after at least 12 seconds; each second thereafter gives them a chance to respawn, with a median wait of about 38 seconds. The vanilla Doom -fast command-line parameter also increases the speed of imp fireballs: they travel twice as fast, and imps throw them persistently while a target remains in sight.

Later versions

In Doom (2016) and Doom Eternal (2020), the imp was redesigned with updated animations and a wider attack repertoire, including a charged fireball variant. Imps are the weakest demon in Doom (2016), which is why they occur in droves throughout the game. These versions are mechanically distinct from the 1993 original, while retaining the imp’s fireball and close-range attacks.

For players of community WADs and source port mods, the imp can be modified through DECORATE or ZScript definitions in GZDoom-based projects, allowing modders to change its attacks, movement, health, or appearance.

Notes

The imp and the zombies are the only monsters in the original Doom with more than one alert sound. The Doom Bible, an early design document for the game, originally envisioned imps as small flying demons. In Heretic, the gargoyle was given a different name to avoid confusion with the imp in Doom.

Tactics: how to defeat the imp

• Strafe sideways when an imp launches a fireball, rather than standing still. The classic fireball travels in a straight line and can be avoided by moving out of its path.
• Use the shotgun to deal with an isolated imp efficiently. An imp can usually be killed with one shotgun shell, while six pistol bullets will often suffice; the result depends on damage rolls and pellet hits.
• Use the super shotgun against a closely grouped pack of imps. A blast will usually kill two imps and can sometimes kill three if they are positioned close enough together.
• Save rockets for larger groups instead of spending one on a lone imp when ammunition is scarce. The rocket launcher can damage several clustered enemies, but its ammunition is valuable and an isolated imp is usually manageable with less powerful weapons.
• Avoid trading claw attacks at point-blank range unless you have a good reason to do so. An imp’s claw attack is faster than a demon’s melee attack, and if the imp’s claw attack misses, it immediately throws a fireball.
• Use the chainsaw against a single imp when it is safe to close the distance. The chainsaw dispatches an imp quickly, but approaching one while other enemies can attack risks being surrounded or hit during the approach.
• Do not expect imps to damage one another with their fireballs. In the original games, projectile attacks from an imp do not damage other imps because of a hard-coded same-species exception; barrel explosions can still hurt them and may trigger infighting.
• On Nightmare! or with -fast enabled, dodge as soon as you see an imp attack. The imp’s fireballs move twice as fast under either condition, and the monster can keep launching them while its target remains in sight.