Be player 2 in the halo 3 co-op campaign. Or, play the Arbiter levels in halo 2.
Another Spartan
You can play 4 player co-op on Halo 3, but not all on the same Xbox. To play 4 player co-op on Halo 3 you can either have 4 people all on different xbox's and use xbox live, or have 2 people on each Xbox and either use Xbox live, or System link to join the parties together.
you don't
Yes, there is co-op in Halo Reach.
There should be a co-op in Halo reach because there was in Halo 3 and ODST why would they stop co-op there?
The second player will also play as Master Chief in a co-op game.
yes it can
yes u go to play multiplayer and then u go to co op then u press a then u play the lvl u want to
Yes, ODST is made for Co-op game play, Both on Xbox Live and Local game play.
yes
Yes, there is a multi-player (odst) campaign and a new HALO 3 disc with a muti-player campaign