Chainsaw

The chainsaw mutilates enemies close enough to contact. At 525 hits per minute, 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 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 33 units, slightly larger than the fist's 32 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 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 and E1M5: Phobos Lab. It is finally found in a non-secret area on E2M6: Halls of the Damned.

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.

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: