Com guid (cvar)


A unique identifier calculated from the supplied CD key, which is used to identify clients in multiplayer games.


At the console type…

com_guid [STRING]


  • [STRING] - Unknown value in string format.


Flag Enabled Description
CVAR_ALL all flags
CVAR_BOOL variable is a boolean
CVAR_INTEGER variable is an integer
CVAR_FLOAT variable is a float
CVAR_SYSTEM X system variable
CVAR_RENDERER renderer variable
CVAR_SOUND sound variable
CVAR_GUI gui variable
CVAR_GAME game variable
CVAR_TOOL tool variable
CVAR_USERINFO sent to servers, available to menu
CVAR_SERVERINFO sent from servers, available to menu
CVAR_NETWORKSYNC cvar is synced from the server to clients
CVAR_STATIC X statically declared, not user created
CVAR_CHEAT variable is considered a cheat
CVAR_NOCHEAT X variable is not considered a cheat
CVAR_INIT can only be set from the command-line
CVAR_ROM X display only, cannot be set by user at all
CVAR_ARCHIVE X set to cause it to be saved to a config file
CVAR_MODIFIED X set when the variable is modified


When the game is started it sends a UDP packet with a ‘gameAuth’ request to the id Software master server (the address of the master server is stored in net_master0). The ‘gameAuth’ request contains the CD key for the main installation and (if installed) the expansion pack.

The master server authenticates the supplied CD keys, generates a guid value and replies with an ‘authKey’ packet. The game then stores the returned guid value in this CVar.

It is speculated that the “client unknown to auth” error is caused by trying to join a game before validating your CD keys with the master server.

When the game connects to an online server the value of com_guid is used to allow the server to identify the player and either accept or reject the connection. Mods that have player management (banning etc) use it to track player data.