doom

Host co-op multiplayer

$ [zandronum-server] -iwad [wad] +map [map] -host [players]

$ [zandronum-server] -iwad [wad] +map [map] -host [players] -deathmatch

Since 'doom' itself is not a standard command, this synopsis represents a common usage pattern with a popular Doom source port, GZDoom, as an example:

gzdoom [options] [-iwad IWAD_file] [-file PWAD_file [PWAD_file2 ...]]

Note: The exact command and its options vary significantly depending on the specific Doom source port installed.

-iwad <file>
    Specifies the primary IWAD file to load (e.g., doom.wad, doom2.wad).

-file <file1> [<file2> ...]
    Loads one or more custom WADs or PK3 files (PWADs) containing mods, levels, or textures.

-warp <map>
    Starts the game directly on a specified map (e.g., E1M1, MAP01).

-skill <level>
    Sets the game difficulty level (1-5).

-host <players>
    Starts a multiplayer server for the specified number of players.

-join <address>
    Joins an existing multiplayer game at the given IP address.

-nosound
    Disables all in-game sound and music.

-fullscreen
    Forces the game to start in fullscreen mode.

-windowed
    Forces the game to start in a windowed mode.

-config <file>
    Uses a specified configuration file instead of the default.

-savedir <directory>
    Sets the directory where save games and configuration files are stored.

-deh <file>
    Loads a Dehacked patch file to modify game behavior.

The 'doom' command on Linux does not refer to a single, universal shell utility but rather to the act of launching a Doom game via a dedicated source port or game engine. Original Doom games require specific game data files, known as IWADs (e.g., DOOM.WAD, DOOM2.WAD), to run. On Linux, users typically install a popular Doom source port such as GZDoom, PrBoom+, or Chocolate Doom through their distribution's package manager. The actual command used will be the executable of the chosen source port (e.g., gzdoom, prboom-plus, chocolate-doom), which then loads the necessary WAD files to start the game. This approach allows players to enjoy the classic first-person shooter experience, often with modern enhancements provided by the source port.

The primary caveat is that a direct doom command is generally not part of standard Linux distributions. Users must first install a Doom source port (e.g., GZDoom, PrBoom+). Additionally, you need the original game's IWAD files, which are typically not included with the source port and must be acquired separately (e.g., from an original game copy or official re-releases). Compatibility with various mods (PWADs/PK3s) can vary between different source ports.

An IWAD (Internal WAD) is the primary game data file containing levels, graphics, sounds, and other core assets of an official Doom game (e.g., DOOM.WAD, DOOM2.WAD). A PWAD (Patch WAD) or PK3/ZIP file is a custom addon created by players, containing new levels, monsters, weapons, or other modifications. PWADs require an IWAD to run and are loaded 'on top' of the base game data.

Several Doom source ports are available, each with different goals. Chocolate Doom aims for perfect emulation of the original DOS executable. PrBoom+ offers a balance of vanilla-like behavior with modern conveniences and demo compatibility. GZDoom is a highly advanced port known for its extensive modding capabilities, true 3D environments, scripting, and support for modern graphics features. The choice depends on whether you prefer a vanilla experience, competitive play, or extensive modding.

Most Doom source ports can be installed via your Linux distribution's package manager (e.g., sudo apt install gzdoom on Debian/Ubuntu, sudo dnf install gzdoom on Fedora). After installation, you typically place your legally acquired IWAD files into a designated directory (often ~/.config/gzdoom/ or ~/.local/share/games/doom/) or specify their path using the -iwad option when launching the game.

The original Doom game, released by id Software in 1993, revolutionized first-person shooters. Its source code was famously released under the GNU GPL in 1997, leading to a proliferation of source ports. These ports are enhanced versions of the original game engine, developed by the community, allowing Doom to run on modern operating systems like Linux, often with improved graphics, sound, and gameplay features. This open-source development has kept Doom alive and thriving for decades, constantly evolving its capabilities and community contributions.

gzdoom(6): A popular, advanced Doom source port., prboom-plus(6): Another widely used Doom source port, focusing on accuracy and competitive play., chocolate-doom(6): A source port aiming for vanilla Doom authenticity., xdg-open(1): Can be used to open a WAD file if a default application is set.