portal-2
I've started playing the coop campaign of Portal 2 during launch break today, and had to stop because of time constraint. I didn't find an option to save the game, so we just disconnected.
Is there a way to save the coop campaign progression? If yes, how does it work? Or will I have to play the whole campaign in a single play session?
Contrary to all the answers on here, it is in fact possible to reset your progress in co-op. Make sure you are the host (you invited your friend, rather than you were invited by your friend). Start a co-op game. Make sure you are in the hub when doing this.
Unfortunately, this doesn't work with ss_map. You have to be in a session with another player, and this will set both players' progress.
Enable the developer console in the options, then press ~ to open it. If you are having trouble, see this question. Then, enter the following command in the console:
mp_mark_all_maps_incomplete
You might see a weird message about DLC, but the command will have no other visible effect. Now, enter this command:
changelevel mp_coop_lobby_2
This will reload the lobby, and your progress will be reset at zero.
You can use this command to change your progress manually:
mp_mark_course_complete <course>
Whereas the number is the number of the course you want to unlock (have finished), minus 1. So to unlock course 1, use mp_mark_course_complete 0, to unlock 2, mp_mark_course_complete 1, and so on. This means that mp_mark_course_complete 0 unlocks course 1 fully, and will then open 2.
There is also mp_mark_all_maps_complete if you want to get Professor Portal.
Thanks to fail badp♦ for allowing me to waste his time.
In the entity list, there is a linked_portal_door for this purpose; it is used in the Death Trap (in map sp_a4_finale2.bsp):
This entity is designed to link two separate, distant areas together without any clear transition between the two. This entity is exclusive to Portal 2.
It is used in Chapter 9, in the Chamber 75 Death Trap with all the crap turrets. The room is actually completely separate from its supposed surroundings. It is the only use of this entity in the final version of the game, though commentary states that it was used a lot during the development of the title to link chambers together.
I guess that the development team first made the rooms separate so that they could wipe a bad room, then connect them later when the levels were more perfect, and I suppose that this room didn't fit.
Here is a picture of the Death Trap that isn't connected to the other rooms:
Near the threshold and a tiny step (noclip fly) to either side:
You might want to skip the commentary and long walk and go to 04:30. From here on he shows the box from outside at the three locations (before box, in box, after box); he first does this slowly, then at a later point he goes between all of them in quicker succession. This might show the trick better than above pictures.
Thanks to Jon Ericson in the comments for finding this video.
Best Answer
Yes, the progress is automatically saved and synced to the Steam Cloud individually - so when you next join a co-op game it will have stored which levels you have completed. This also means that your progress is shared across any computer you play Portal 2 on.
It's worth noting that progress is never saved during a test chamber though, only upon successful completion.
You will be able to pick which level to start at next time you start the game - if you go to the specific chapter you want to play and use the buttons until you've selected the level you want, then go into the assembly machine as usual.