You can buy both the standard and limited editions on PSN or buy a physical copy. If you buy the physical the disc is NOT required to play the game. Though I have not done so in some time, back when the game first started on PS3, launching from the disc did improve stability to some small extent but not enough to be a deciding factor. If you got a digital version and wanted to use a disc for some reason you could, all that matters is the registration code you get/got when purchasing the game initially. Note that if you ever wanted to change to PC you would need a new code but if upgrading to PS4, as of right now, they will allow you to transfer your PS3 code to PS4 for free. Hope this helps.