A game session is a new concept introduced for [[version_1_9.7]] which collects together the functionality of the [[-game]], [[-iwad]], [[-file]] and [[-def]] command line arguments and combines them into a "session".

Game sessions specify the game being played and the list of resources to be used (and more) which collectively //define// the current session of play. A [[doomsday]] game session is roughly analogous to a [[snowberry]] profile.

Doomsday presently implements only one game session, i.e., that which is currently being played. Arguments specified on the command line serve to initially configure this session, which if valid, is then loaded automatically during engine startup (unless the [[-noautoselect]] argument is also specified).

Once startup completes the current game session may be modified at any time using the console [[ringzero_cli|ringzero cli]].