Rocket Launcher

The classic rocket launcher uses a projectile rather than a hitscan attack, so the rocket takes time to reach its target. Its explosion can damage several enemies at once, but the same blast rules apply to the player and can make close-range use dangerous. The weapon’s behavior also differs between the original games and later Doom releases.

First appearance and placement

The rocket launcher makes its earliest appearance in a secret area of E1M3: Toxin Refinery, and continues to appear in secret areas across the next three levels of Knee-Deep in the Dead. It is not placed in a non-secret area until E1M7: Computer Station. In Doom II, it is available from MAP01: Entryway.

Combat characteristics

Each rocket inflicts between 20 and 160 points of direct-hit damage, determined in round multiples of 20 via Doom’s pseudorandom number generator. The explosion has a maximum blast radius of 128 map units, but that figure describes its reach, not a fixed amount of damage. Blast damage is calculated as 128 minus the distance from the explosion to the target’s edge. The engine uses whichever is greater of the horizontal x- and y-offsets, subtracts the target’s radius, and checks line of sight; it does not include vertical distance.

A direct hit also causes blast damage, but it does not normally deliver the full 128-point maximum: the rocket’s explosion occurs at its last position before the blocked movement step, leaving a gap between the explosion center and the target. A direct hit therefore adds approximately 103–117 points of blast damage to the 20–160-point direct-hit roll, for a combined total of approximately 123–277 points. Cyberdemons and spider masterminds are immune to blast damage, so rockets damage them through the direct-hit component only.

The rocket launcher’s damage per shot is comparable to that of the super shotgun, but its faster firing rate of 105 shots per minute, compared with the super shotgun’s 41.2 shots per minute, gives it a higher potential damage output over time.

Ammo and inventory

When the rocket launcher is picked up from the floor as a weapon item, it comes loaded with 2 rockets, or 4 rockets on the I’m Too Young To Die and Nightmare! skill levels. The player can carry a maximum of 50 rockets, expandable to 100 with a backpack. Rockets are individually pickable items (thing type 2010) and also come in box form. The 50-rocket limit means that ammunition management matters, particularly when using rockets against enemies that can be defeated with less costly weapons.

The safety catch

The rocket launcher incorporates a behavior informally known as the safety catch, shared with the BFG 9000. If the player switches to the rocket launcher while the fire button is already held down, the weapon will not fire immediately — it only fires once the fire key is released and pressed again. The behavior is documented as a weapon-switching quirk; its original design intention is not established by the available evidence.

Rocket jumping

The rocket launcher is central to one of Doom’s most enduring mechanics: rocket jumping. In the original Doom engine, the player cannot aim the weapon down at the floor, and an explosion does not provide vertical lift. Instead, the blast adds horizontal momentum, allowing the player to travel farther than normal movement permits. It does not let the player rise beyond the engine’s 24-unit step height. Vertical rocket jumps are possible in source ports that support vertical aiming and vertical explosion thrust, allowing the player to use rocket explosions to gain height. According to John Romero, Tom Hall originated the technique during development when he tried to reach the secret exit area in E3M6: Mt. Erebus.

A related engine quirk is that a rocket passes through the player who fired it. This does not make the player immune to the explosion: the blast can still cause self-damage if it detonates nearby.

Tactical considerations

The rocket launcher’s splash damage makes it effective against tightly packed groups of monsters, capable of damaging multiple targets with a single shot. This is offset by a significant risk: firing in enclosed spaces or at close range poses a serious self-damage hazard. Even a player at 200% health and maximum armor can be killed by a series of accidental close-range detonations.

The weapon’s vertical auto-aim can adjust a rocket’s trajectory to target an enemy above or below the player’s horizontal line of aim. However, classic Doom’s blast calculation ignores vertical distance, so an explosion can damage targets directly above or below it if they are within the horizontal blast area and have line of sight.

Using the rocket launcher around lost souls or pain elementals is hazardous: lost souls charge straight at you, and pain elementals keep spawning them close by, so the explosions often go off near the player. Against tougher, isolated targets such as barons of hell or mancubi, rockets can deliver substantial direct-hit and blast damage; cyberdemons and spider masterminds are exceptions because they are immune to blast damage.

Doom 64 variant

The Doom 64 version of the rocket launcher shares most of its properties with the original but differs in several measurable ways. Its rocket projectile travels at 30 map units per tic (900 map units per second), compared with the original’s 20 map units per tic (700 map units per second). The Doom 64 launcher also delivers knockback to the player when fired, a behavior not present in the original version. Its rate of fire is slightly lower at 100.0 shots per minute. The weapon’s sprite is visually distinct from the original’s MISG frames, using the ROCK sprite set instead. Its earliest appearance is on MAP32: Hectic, the game’s first secret level, which is reached through a hidden procedure on MAP01: Staging Area.

In the modern games

The rocket launcher has different implementations in later Doom games. In Doom 3, it uses a five-rocket magazine and is first found in Recycling Sector 1.

In Doom (2016), the launcher adds a Remote Detonation modification, which lets the player detonate rockets while they are in flight. Its standard rocket deals 130 points of direct damage, while its splash damage can reach 350 points within a 320-unit radius.

In Doom Eternal, the weapon is also called the Paingiver. Compared with the Doom (2016) launcher, it fires more slowly and its rockets fly slower, but they do more damage and have a larger blast radius. It is first obtained in the Cultist Base.

For more information on Doom’s arsenal and the monsters you’ll encounter, explore our Doom weapons and Doom enemies databases.