Even though recent comments from Bungie citing technical challenges hinted that online co-operative gameplay was on the brink of not making it to Halo 3, the game developer finally calmed the anxiety of Halo fans by announcing a surprising four-player co-op in campaign mode on Xbox Live or System Link.

So you were probably wondering why we didnít want to commit to two player co-op online over Xbox Live. We certainly got plenty of mail asking, no, demanding that we make it happen. Of course we were working on it, but we were also working on something better. Not two player co-op. Not three-player co-op, but up to four player co-op. Online. On Xbox Live, or sure, System Link if you prefer.
Bungie also opted to avoid having the slightly surreal compromise of two identical Master Chiefs running around together. Instead, each of the four players will be assigned to a pre-determined warrior: Master Chief, Arbiter, and two new Elite characters. Hopefully, Bungie will overcome any lag issues caused by the network challenges this new mode could present. Furthermore, players who start a single-player campaign will also be able to bring in other gamers to join in the adventure from any save checkpoint.

The latest incarnation of the wildly successful Halo series will be available on September 25 in three versions Ė standard edition, limited edition, and legendary edition. Bungie said itíll be revealing more details on how the co-op will work in the very near future.