$OpenBSD$

To play the game you will need an original Doom, Ultimate Doom, Doom
II, Final Doom, Heretic, Hexen, or Strife IWAD. Place the doom.wad,
doom2.wad, plutonia.wad, tnt.wad, heretic.wad, hexen.wad, strife1.wad
+ voices.wad or all of the above in ${PREFIX}/share/doom/ to play. If
a file loaded require some assets it will also check the files in this
folder.

If multiple files are needed for a mod, you may specify a list of
files of want to load via the command-line parameter e.g.

  $ gzdoom textures.wad alien_doom.wad
  $ gzdoom heretic1.wad (heretic shareware)

The Doom Shareware IWAD is available in the doomdata package.