Quit messages

When the player attempts to exit Doom, a funny quit message is shown, convincing the player to stay and play some more. The message is chosen randomly out of a pool of seven, different for each game. The player must then confirm that they want to exit, by pressing 'Y'.

Extras
When the Doom source code was released, the following extra quit messages were found in the source. According to John Romero, these are development mode only quit messages that were never to be seen in a real release version.