Stupid game? I must be a real idiot then because I loved all 3 of them!
ME3 is Origin based and you can have it on as many computers as you want. You can only be logged into your account on one computer at a time though of course. Origin is just like Steam. If you get tired on the game for a few years and uninstall it and then want to play again all you have to do is download it again. Or even if your computer dies all you would have to do is log into Origin and download it again on a new computer.