Gameplay

This document is by no means complete, and should by no means be refered to as an absolute authority on the gameplay of Doom.

Movement

In Doom, there are several 'bugs' in regular movement that have over time been come to be known as features of the Doom engine. See The Doom Wiki for completeness.

Straferunning

This is done by moving forward and strafing left or right at the same time, which allows you to move faster than you would normally by just running forward or backwards. This is a basic movement which, when the game has been played often, is essentially a natural and effortless maneuver.

SR50

SR50 stands for "straferun 50", and is basically a variant of straferun that allows you to move even faster than normal straferunning. This maneuver is accomplished by simultaneously mouse-strafing and straferunning. To SR50, you move your mouse in the same direction as your straferun. While in SR50, you can not turn around due to mouse-strafing, so you sacrifice aim for mobility. This is a more advanced maneuver and is harder to control, but it is useful at times, especially for reaching a distant point faster or dodging an enemy's fire.

Backwards Movement

Although its use is limited, backward movement is actually faster than moving forward. Straferunning backwards is thereupon proportionally faster.

Wallrun

If you straferun at a certain angle against a straight wall while moving from north to south or from east to west, you actually gain even more speed than SR50. There is a server setting that enables wallrunning in all cardinal directions, but by default, wallruns are only achieved in the two said directions -- from north to south, and from east to west.

Weapons

Weapons in Doom are differently balanced than in most other games.

Combat Shotgun

This is the most used weapon in Doom multiplayer. The combat shotgun, commonly referred to as the "super shotgun" or abbreviated as "SSG", is usually an abundant weapon on any given multiplayer map, and because of the powerful blows it can deliver, an accurate shot can kill an opponent in one hit. However, the main drawback is that it takes a second or two to reload allowing other players to take advantage of this. It becomes inaccurate past medium range due to its large spread, and is thus most suitable for combat in closed, short-range areas.

BFG 9000

The BFG9000 fires a large, green, and slow-moving projectile that can easily gib an enemy in a direct hit. After impact of this projectile, a "cone" of invisible tracers emit from the position of the player in the direction the player was facing after firing the BFG, regardless of the player's new position and orientation. The BFG9000's use can become highly complicated due to the many advantages and uses of the said tracers and the difficulty that can be experienced while dodging the tracers. This weapon is very often criticized for being overpowered and unfair by lesser experienced players, however in a classic 1-on-1 game this weapon is considered balanced.

For a full explanation on how the BFG works, please read The BFG FAQ. Once you learn how this weapon works, it is remarkably easy to dodge in a 1-on-1 fight and using it can become much easier.

Rocket Launcher

The rocket launcher is a powerful projectile weapon that can easily kill in one hit. However, unlike rocket launchers in modern games, the rockets this weapon fires are slow; so slow that a straferunning player can actually outrun their own rocket easily, given enough space. Another drawback to the rocket launcher is that it can produce a great amount of splash damage to the player firing it.

Chaingun

This weapon is most useful at long range combat, or chasing down a fast moving player. The chaingun fires small shots rapidly and thus has the ability to constantly disorient an opponent with the near-persistent amount of red-screen build-up it causes, which can affect the opponent's aim. The first two shots of the chaingun are the perfectly accurate, while subsequent shots are not, a phenomenon referred to as "chaingun recoil". Therefore, to maintain accuracy with the chaingun, one must tap the fire button repeatedly instead of continuously pushing it down so that the first few shots would be fired continuously.

Plasma Rifle

Another projectile weapon, the plasma rifle shoots fast blue balls of plasma that can cause a considerable amount of damage, and is one of the more efficient weapons. The pinnacle of its efficiency is seen at close-range combat, where it is difficult for the adversary to escape the flying projectiles. The main disadvantage of the plasma rifle is that the projectiles can obstruct the view of the user making is somwhat difficult to see.

Shotgun

The shotgun is a relatively weak weapon compared especially to the super shotgun, but its tight pellet spread does not subside at long range, making it a decent weapon to 'ping' people at long range with. It proves a fairly fast-killing weapon at close range, where its pellets are more concentrated. Although extremely rare, it is possible to kill an opponent at 100% health with no armor with only one shotgun round.

Other

There are four other weapons, all of which are of dubious value. The pistol, the default weapon any player first starts with, is far too slow to even consider using in a very practical sense. The fist and chainsaw are melee weapons which require for one to be as close as possible to another player to damage them. However, the chainsaw can be a very deadly weapon, as can the fist when a berserk pack has been picked up.