Steam

Every official Doom game and various other commercial games based on the Doom and Doom 3 engines have been released on Valve's content delivery system Steam. Most of the games were made available on August 03, 2007.

On Steam, classic Doom games and other games that use the Doom engine by default run under the DOSBox emulator, but it is also possible to use source ports with the games. More information on this below.

Classic Doom games

 * The Ultimate Doom ($9.99)
 * Doom II with Master Levels ($9.99)
 * Final Doom ($9.99)

Doom engine games

 * Heretic: Shadow of the Serpent Riders ($4.99)
 * Hexen ($4.99)
 * Hexen: Deathkings of the Dark Citadel ($4.99)

Doom 3

 * Doom 3 ($19.99)
 * Doom 3: Resurrection of Evil ($19.99)

Doom 3 engine games

 * Enemy Territory: Quake Wars ($14.99)
 * Prey ($24.99)

How to use source ports with games downloaded from Steam
First, download the archive that contains the source port executable and other files necessary to run it. Then decompress the source port archive, and put all the files/folders into the folder \SteamApps\Common\\base. Running the source port main executable (for example, zdoom.exe or prboom.exe) should then start the game.

Alternatively, the IWAD (named doom2.wad for Doom II, hexen.wad for Hexen, etc.) can be copied from \SteamApps\Common\\base to a directory of your choosing and the source port files decompressed/copied there. Again, running the source port main executable should then start the game.

If you wish to run the games with a source port while using the original Steam shortcuts you need to decompress and copy the source port files to <Steam directory>\SteamApps\Common\<game name>\base</tt> as instructed below. Then you need to edit the .bat</tt> files located in <Steam directory>\SteamApps\Common\<game name></tt> (bat files can be edited with any text editor, such as the Windows Notepad). Doom II, for example, has two files, doom2 + mouse.bat</tt> and doom2.bat</tt>. If you wish to have mouse support enabled, edit doom2 + mouse.bat</tt>, otherwise doom2.bat</tt>. The files contain the following type of text: .\base\dosbox -conf .\base\doom2m.conf -fullscreen -exit exit You should then edit the top line to point to the main executable of the source port. For example, for ZDoom it would be as follows: .\base\zdoom.exe After this the Steam shortcuts should launch the source port version of the game.