While it does low damage per shot, its quick firing speed and long-range capabilities, as well as its plentiful ammo and ability to fire underwater, make it a very useful sidearm. It is first acquired when Doomguy visits the shooting range in Chapter 1. Pistol: The starting ranged weapon of the game, replacing the Glock 17 from Half-Life.Chainsaw: A rapid-use melee weapon that does not have a Half-Life counterpart.Doomguy automatically starts with this weapon. Due to its low damage and poor range, it should only be used as a last resort or when under the effects of the Berserk Power.

Fists: The starting melee weapon of the game, replacing the Crowbar from Half-Life.Soldiers simply provide cover fire for the player with rocket launchers and assault rifles, Heavies use heavy machine guns to attack enemies and can use energy shields to protect allies, Medics carry an unlimited supply of medicine that they can use to heal the player and other NPCs while fighting with submachine guns, Engineers will cut open certain doors and repair certain objects for the player while using revolvers to defend themselves, and Scouts can detect hidden enemies and alert the player to a unobserved environment while wielding shotguns to fight enemies. While the player spends most of the game alone, they are occasionally accompanied by non-playable characters, mainly other marines with different abilities. The player is able to perform a high jump by crouching for a period then jumping, combat roll in any direction, and pick up various objects for usage as brief melee weapons. Other obstacles include pits of toxic waste, locked doors that require a keycard or flipped switch to open, enemy fortifications and gauntlets of hazards that the player must transverse. The mod features all the weapons and monsters from Doom, Doom II, and Doom 64, as well as a handful of new weapons and enemies. Progress through the world is as continuous as to be expected, with scripted sequences in place of cutscenes and the player kept in complete control of the first-person narrative throughout most of the game. Due to its dedication to the gameplay style of the original Doom, the mod features a heavier emphasis upon combat over puzzles, although the latter is still utilized fairly regularly, compared to Half-Life. Players are required to navigate through levels, fight enemies, solve puzzles and monitor their supplies of health and armour. As a mod for Half-Life, the gameplay of Half-Life: Doom does not significantly differ from the base game.

Half life rocket launcher