Quote Originally Posted by Bayar View Post
Seeing as how I was able to copy-paste Jagged Alliance 2 on another folder and patch it to 1.13 and play it without even starting up Steam, that might be possible.
That only works for certain games. (Usually non-steamwork based games or old games which have been ported over to Steam. AI War is one such game.)

I haven't tried actually installing a game without connection though, but I am reasonably certain Steam needs an internet connection to verify the game files and download any that might be missing. Need to investigate this further.