I have read that when "Play as Guest" mode is selected, Starcraft II campaigns can be played without achievements being recorded to your profile.
Every time I click to the "Play as Guest" button, it tells me to authorize my game client. Then I login. Because game does not allow me to switch to guest mode I exit the game. I relaunch the game. And finally I can play as guest without internet connection.
At the moment I am sharing a 3G modem with my father so I can't be online all the time, and I am sick of doing this "login, close, open" every time.
Do you have any idea what might be wrong?
Best Answer
You have to log in at least once before you can play offline. Trying to log in without an internet connection causes it to look for a profile that it can load. If it finds one, it will let you play offline with the caveat that achievements are disabled. If it cannot find a profile, you'll get the error you describe about authorizing the game client. You'll need to get internet access to create the profile before you can play with it offline.
Beyond that, the game should let you log in as a guest, log out, and log back in as a guest without having to log in. I just tested this with my laptop on a fresh install of the game. It gave the error until I logged in the first time. Then, I disabled wifi access and was able to log in several times as a guest.
A caveat: The game requires you to log in once ever 30 days to re-verify the game to ensure you're not sharing the key with other people. This has been confirmed by Blizzard.