User blog comment:JordanaBrewsterFAN/Mass Effect internet/@comment-4618888-20120627202603

You don't need to be connected to the Internet to play. You do have to create an EA account to play Mass Effect 2 and/or 3 and be connected when you first open the game(s) to validate them. I'm not sure about the first ME, but I don't think you need to be connected at all.