Okay so basically I’m playing the “Cross-Game” playlist. My question is, can I play either Halo CE, 2, 3 or 4 playlist WITHOUT resetting any progress in the Cross-Game playlist?
Are you referring to the cross-game campaign palylists? Or are you referring to matchmaking?
If you’re talking about campaign, each group of playlists tracks itself independent of the others. For example, if you have progress in a cross-game playlist, you can do whatever you want in the h1, H2, H3, or H4 playlists without affecting anything in the cross-game playlists. However, if you start a new cross-game playlist, that will overwrite your progress in the other cross-game playlist that you had already started.
The only thing I’m unsure of is whether or not there is a distinction between H3 and H3:ODST playlists. All the others are definitely separated though.