When saving a game in Vanilla Doom, some game options are not preserved. This includes the following settings:
- Respawning monsters (-respawn)
- Fast monsters (-fast)
- No monsters (-nomonsters)
- Deathmatch (-deathmatch and -altdeath)
The affected options are mainly relevant when playing multiplayer. When restoring a network savegame, the bug can be circumvented by adding the appropriate options onto the command line.
The function G_DoSaveGame in g_game.c is the entrypoint into the code which saves games. This writes a "header" to savegame files which contains game options. The game options saved are the skill level, episode and map, and a list of players in the game. Any other options are not saved.