Chainsaw

From DoomWiki.org

A chainsaw on a ledge in MAP15: Industrial Zone from Doom II.
The chainsaw, near where it is found in E1M2: Nuclear Plant.
This article is about the weapon in the classic Doom series. For other versions of this weapon, see:

The chainsaw mutilates enemies close enough to contact. At 525 hits per minute (one hit every 4 tics), it is roughly a quadruple-speed fist. Its "rapid fire" works well on enemies with high pain chance, minimizing damage to the player in melee situations. It is often used to conserve ammo or simply because of its gory implications. When picked up, the message is "A Chainsaw! Find some meat!". It is officially described as such:

"Chainsaw cuts the baddies like standing timber, but you have to get close."

Tactical analysis[edit]

A player, holding a chainsaw, finding another one in MAP22: Burnt Offerings from Doom 64.

The chainsaw is a strong melee weapon, but due to its limited range it is impractical to use against certain types of monsters. It is most effective against demons and spectres, since the player can usually kill them without taking damage. The chainsaw's disadvantage is its slow killing speed compared to the berserk fist, which becomes a liability when facing multiple enemies in open areas. Expert players confronted by a pack of demons and spectres back into a corner and chainsaw them down one by one; if the corner is less than 107 degrees wide, only one demon can attack at a time.

The chainsaw has a range of 65 map units, slightly larger than the fist's 64 units.

It can also be used fairly effectively against cacodemons, pain elementals, lost souls, and imps. A safe application against revenants requires a difficult method of continuously backing off, maintaining a distance too far for its fists and too close for its rockets. It is ineffective against Hell knights and other demons with powerful attacks and low pain chance. A safe and easy usage against zombies is possible when waiting behind a sharp corner, but two things must be considered. First, zombies often advance in a zig-zag pattern. Second, using the chainsaw behind doors may cost more ammo than it saves if the dropped weapon or ammo is not picked up and smashed in the closing door. When used against mancubi, the monster may suddenly start to retaliate; this risk may somewhat be lowered by using several short attacks.

The chainsaw is effectively rendered useless against demons and imps if the game is played with the -fast parameter (such as in Nightmare! difficulty), since these monsters' melee attacks are two times as fast, and they also recover from pain state twice as fast.

The chainsaw first appears in a secret area of the level E1M2: Nuclear Plant, and appears again in secret areas of E1M3: Toxin Refinery and E1M5: Phobos Lab. It is finally found in a non-secret area on E2M6: Halls of the Damned. In Doom II, it can be found in an optional area at MAP01: Entryway at the very start of the map.

In vanilla Doom, if a player has a chainsaw, they cannot switch back to the fists unless they have a berserk pack. Most modern source ports allow toggling of the fists and chainsaw by pressing "1" (as with the two shotguns in Doom II).

The chainsaw can be obtained via the cheat codes idchoppers, idfa or idkfa.

Inspiration and development[edit]

The "Eager Beaver" chainsaw borrowed by Tom Hall about to be photographed.

The chainsaw graphics are based on scans of a real chainsaw, a McCulloch Eager Beaver, borrowed by Tom Hall from his then-girlfriend.

The addition of the chainsaw to Doom, along with the shotgun, was inspired by the 1987 comedy horror film Evil Dead II. In the film, the protagonist Ash, having lost his right hand to a demonic infection, modifies a chainsaw and attaches it to his stump arm, using it to slay the undead.

The chainsaw was a slightly later addition to the game's arsenal which is not described in the Doom Bible. A crude, early pickup sprite appears in Doom v0.3. Its first-person and normal pickup sprites first appear in Doom v0.4 alpha, but it does not become functional until the press release beta.

Notes[edit]

  • Total number and timing of the chainsaw's animation frames are identical to those of the chaingun; as a result, they have the same rate of fire. The chainsaw however deals slightly higher damage per second, as the mean damage of a single tooth is higher that a bullet's. Specifically, the chainsaw's A_Saw() function does (x + 1) * 2 damage, where "x" is a random number between 0 and 9. The chaingun's A_FireCGun() function instead does x * 5 damage, where "x" is a random value between 1 and 3.
  • Due to flawed collision detection, the chainsaw is ineffective against the arachnotron, mancubus and spider mastermind without a source port that modifies vanilla hitscan behavior.
  • Switching to the chainsaw means that there is a continuous buzzing from the chainsaw motor. When "fired", the chainsaw is shoved forward and the buzzing changes to a higher and even more intense whine. Like gunfire or a fist punch, attacking with the chainsaw will alert monsters in open areas, however merely switching to the chainsaw will not. Players who often want to provoke enemies into finding them can "fire" the chainsaw, without wasting ammo.
  • Doom 64's chainsaw is drastically different in terms of appearance. The saw has two blades instead of one and the letters "U.A.C." are engraved on top of the weapon. The damage inflicted by this version of the weapon is roughly doubled, causing damage once every 2 tics (0.066 seconds in Doom 64's slower rate of 30 tics per second), and the damage formula is (x + 1) * 3, where "x" is a random value between 0 and 7.
  • The TV advertisement for the Sega 32X port showed numerous instances of the player chainsawing imps and demons, intercut with images of butchers at a slaughterhouse/meat factory.
  • The chainsaw appears to have no discernible reason to be on Phobos as the moon appears to be devoid of plant life. This would be parodied in later entries, with Doom 3 mentioning a shipment of chainsaws being delivered to Mars by mistake instead of the requested jackhammers, and Doom (2016) noting that the chainsaw was smuggled in before it was confiscated by security.
  • Due to a limitation of the game engine, the chainsaw does not penetrate its victims; instead, it repeatedly re-aligns the player's position to give the effect of being 'locked' with the target. This can be observed by simultaneously sawing a demon and attempting to turn with the mouse.
  • The chainsaw "rev up" sound (DSSAWUP) is played when the player switches weapons to the chainsaw. Normally it is not played in its entirety, as the sound is cut off by the normal sound effect made by the chainsaw while selected (DSSAWIDL). It can be heard in its entirety by switching weapons to the chainsaw from any other weapon, and immediately pausing the game; and is also played completely when a new level starts with the active weapon being a chainsaw (see Intermission screen#Chainsaw sound effect). Likewise the attack sound is longer than is normally heard; if the game is paused while attacking, a much longer and higher pitched portion of the sound can be heard.
  • The idchoppers cheat code which gives the chainsaw is also supposed to make the player invulnerable; however because of a confusion between a countdown timer and a boolean value, this invulnerability only lasts a single tic. From st_stuff.c:
// 'choppers' invulnerability & chainsaw
else if (cht_CheckCheat(&cheat_choppers, ev->data1))
{
	plyr->weaponowned[wp_chainsaw] = true;
	plyr->powers[pw_invulnerability] = true; '''// this value is supposed to be how long the power lasts'''
	plyr->message = STSTR_CHOPPERS;
}

Data[edit]

The original chainsaw can inflict approximately 94.47 points of damage per second:

Seconds needed to kill1 Mean Standard
deviation
Min Max
Barrel 0.27 0.09 0.11 0.57
Zombieman 0.27 0.09 0.11 0.57
Shotgun guy 0.38 0.11 0.23 0.80
Wolfenstein SS 0.60 0.14 0.34 1.03
Imp 0.70 0.14 0.46 1.14
Heavy weapon dude 0.80 0.15 0.46 1.26
Lost soul 1.12 0.18 0.80 1.60
Commander Keen 1.12 0.18 0.80 1.60
Demon 1.65 0.21 1.14 2.17
Spectre 1.65 0.21 1.14 2.17
Romero's head2 2.70 0.24 2.06 3.20
Revenant 3.23 0.25 2.51 3.66
Cacodemon 4.29 0.29 3.43 5.03
Pain elemental 4.29 0.29 3.43 5.03
Hell knight 5.33 0.27 4.57 5.94
Arachnotron3 5.33 0.27 4.57 5.94
Mancubus3 6.39 0.25 5.83 6.97
Arch-vile 7.46 0.23 6.86 8.00
Baron of Hell 10.64 0.23 10.06 11.20
Spiderdemon3 31.80 0.23 31.20 32.34
Cyberdemon3 42.38 0.28 41.71 43.20

  1. This table assumes that all calls to P_Random for damage, pain chance, and blood splats 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). 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.
  3. Due to errors in the line-of-sight algorithms of vanilla Doom (see Spider paralysis), it is sometimes impossible to keep the chainsaw in continuous contact with a wide monster.

Appearance statistics[edit]

In the IWADs the chainsaw is first encountered on these maps per skill level:

The IWADs contain the following numbers of chainsaws per skill level:

See also[edit]

External links[edit]