Bungie announced that the reason for which they delayed releasing details about the craved two player co-op mode for Halo 3 is their intensive work for a “better” co-op, meaning…four players.

“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.

That is correct – up to four player co-op in Campaign mode on Xbox Live or System Link.”

Apparently Bungie kept quiet about its progress with the co-op mode because they wanted it to be the best experience ever for the potential players, and… because they had too much fun playing.

“We’ve been playing it for quite some time, and bluntly, having some of our greatest ever Halo experiences. We wanted to make sure all our “t”s were crossed and our “i”s dotted before unveiling this important new part of Halo 3’s Campaign mode.

Apart from the horrifying network challenges this new mode presented us, were the various gameplay balance issues it adds to the fray. So we got it all together, polished it, and that’s why we’re revealing it now. As a result, you’re going to want to play co-op as hard as you can stomach it. We’d certainly recommend Legendary, but we’ll be revealing some more ways to make the game more interesting and challenging for multiple players in the very near future.”

The Bungie team is definitely excited about Halo 3’s Campaign gameplay in co-op mode and the official blog states that “The combinations and scenarios are endless – and you’ll be able to enjoy them time and time again in Saved Films of your co-op exploits.”

“Like every other aspect of Halo 3, this mode is chosen from a Lobby. Simply select Campaign, choose your network (Xbox Live or System Link) and invite your friends to join you, or they can simply join your session once it’s set up and in a lobby (but they cannot join a game once it’s in-progress). They will pop into your lobby instantly, and when you have all the players you need (anywhere from one to four) you can begin the game from the beginning – or from any of your saved checkpoints.

Split-screen co-op is as ever, limited to two players per screen – but they can if they wish join two other friends online or via System Link.”

Bungie didn’t want two Masterchiefs appearing on the screen so it decided expand the gameplay with two new Elite characters (besides Masterchief and Arbiter), which will have identical abilities, but different weapons at the beginning (Elites will start with Carbines versus Battle Rifles for example, depending on the mission).

The two are N’tho ‘Sraom (“the youngest member of his Special Operations unit”) and the Usze ‘Taham.