Weapon

Doom
No matter which weapon a player is wielding, his sprite (in multiplayer games, or source ports with a "chasecam" mode) is perpetually shown to be armed with the same generic assault rifle as the former human troopers; a weapon similar to this, although presumably intended to be the chaingun, appears on the game's title screen.

Doom Alpha
Early alpha releases of Doom armed the player with a semi-automatic rifle, optionally equipped with a double-bladed bayonet as a melee weapon. This weapon was not included in the finished game. The firing sequence animation was unique, and revealed the player character to be wearing elbow pads, which can still be seen on the player character sprite.

Doom/Ultimate Doom

 * Fists: Weak, but never runs out of ammo. Especially useful with the berserk pack.
 * Chainsaw: Does damage like the normal fist, but four times faster.
 * Pistol: The default long-range weapon. Not too effective.
 * Shotgun: A good general-purpose weapon, especially at close range. Reload time is slightly longer than normal.
 * Chaingun: Very good against large crowds, but uses up a lot of ammo if not handled carefully.
 * Rocket launcher: Fires explosive rockets. Does a lot of damage, but can also seriously hurt the player if used indiscriminately at close range.
 * Plasma gun: Shoots pulses of blue-hot plasma at high speed, which can take down groups of incoming enemies easily &mdash; if aimed properly.
 * BFG 9000: The big gun. Somewhat counterintuitive to operate at first, but kills almost any monster in one shot.

Doom II/Final Doom
All of the above weapons, with the addition of:


 * Super shotgun: A double-barrelled, sawed-off shotgun which takes even longer to reload, but at close-range is even more deadly than the regular shotgun.

Doom 3
All of Doom's weapons are present in some form in Doom 3, with the addition of:


 * Flashlight: Not a weapon per se, but it doubles as a crude club.
 * Machine Gun: Similar to the chaingun, but not as powerful.
 * Grenades: Standard thrown fragmentation grenades on a timer.
 * Soul Cube: Charged by the killing of monsters, and then released as a powerful seeking weapon that transfers health from the monster it hits to the player.

Resurrection of Evil
The Doom 3: Resurrection of Evil expansion pack contains all of Doom 3's weapons, as well as a rendition of Doom 2's super shotgun.

Skulltag
Skulltag supports a few extra weapons that can be added to Skulltag maps:


 * Minigun: Even faster than the chaingun, but has a cooldown pause when the trigger is released, and no first-shot accuracy.
 * Grenade launcher: Fires bouncy, explosive grenades.
 * Railgun: Fires hitscan rails that can pierce multiple enemies.
 * BFG 10000: Unleashes rapid-fire, hitscan bolts with splash damage which can affect a large area.

Heretic

 * Dragon Claw
 * Elven Wand
 * Ethereal Crossbow
 * Firemace
 * Gauntlets of the Necromancer
 * Hellstaff
 * Phoenix Rod
 * Staff

Hexen
Fighter Cleric Mage
 * Spiked Gauntlets
 * Timon's Axe
 * Hammer of Retribution
 * Quietus
 * Mace of Contrition
 * Serpent Staff
 * Firestorm
 * Wraithverge
 * Sapphire Wand
 * Frost Shards
 * Arc Of Death
 * Bloodscourge

Strife

 * Punch Dagger
 * Crossbow
 * Assault Gun
 * Mini-Missile Launcher
 * Flamethrower
 * Grenade Launcher
 * Mauler
 * The Sigil of the One God