Chainsaw

''This article is about the original Doom games weapon. For the weapon in Doom 3, see Chainsaw (Doom 3). For the weapon in Doom 4, see Chainsaw (Doom 4).''

The chainsaw is a melee-based weapon that has appeared in every Doom title in the series. This weapon mutilates enemies close enough to contact. At 525 hits per minute, it is roughly a quadruple-speed fist. It is often used because it conserves ammo, its "rapid fire" works well on enemies with high pain chance, which minimizes damage in melee situations, and because of its gory implications.

When picked up, the message is "A Chainsaw! Find some meat!". The TV advertisement for the Super Nintendo port showed numerous instances of the player chainsawing Imps and Demons, intercut with images of butchers at a slaughterhouse/meat factory.

Strangely, the chainsaw appears to have no discernible reason to be on Phobos, Deimos, or Mars, as these places appear to be entirely devoid of plant life. This is parodied in Doom 3 and Doom RPG II by having a shipment of chainsaws received as a mistake, as the Mars City base had in fact ordered jackhammers to aid in their excavations (the chainsaw turns out to be a very strong weapon for killing monsters, even Hell Knights). However, it is possible that it is a Diamond bladed chainsaw, which is commonly used for cutting rock, concrete and other stone-like materials. These mostly look the same as a normal chainsaw, so it would be hard to tell from in-game material.

It is considered to be most effectively used against Demons and Spectres, since the player can more than likely kill them without taking damage. The chainsaw's disadvantage is its slow killing speed, compared to the berserked fist, which becomes a liability when facing multiple enemies and 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).

It can also be used fairly effectively against Cacodemons, Pain Elementals, Lost Souls, and Imps. Can be used against Arachnotrons, though the approach must be as fast as possible. 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 ranged attacks. 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 parameter is set to Fast Monsters (such as in Nightmare difficulty), since these monsters' melee attacks are three times 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, E1M5: Phobos Lab and E1M7: Computer Station.

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). Newer source ports have allowed other instances of toggling between 2 weapons with other keys, including the Railgun (can be toggled with plasma rifle) and the BFG10K (can be toggled with BFG 9000) in Skulltag.

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

Data
The chainsaw can inflict approximately 94.47 points of damage per second:
 * 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
The IWADs contain the following numbers of chainsaws: