Lodan aha said:For infection mutation outbreak and quaritian you dont NEED the disks that came before it (like 3 can be played without svaed files from 2 or 1) but you will miss out on alot and there are gifts and secrets that are given if you have data flags from th other games when you finish a disk. Also the DVD's that come with the games are semi-importent to the story line of the games..although again you could do without. ^_^ I also cant wait for goey (nickname we made dont ask)