Essentially revealed yesterday via a pair of magazine covers, BioWare has gone ahead and taken the extra step of extra-super-duper confirming the fact that Mass Effect 3 will have a multiplayer mode, and even was nice enough to provide a few details on how the whole thing works. Awfully nice of them, no?
Multiplayer comes in the form of a four-player cooperative mission suite, in which players will each choose a character, and combine forces using their own unique "weapons, powers, and abilities to devastating effect as they fight together to liberate key territories from enemy control." The multiplayer mode is not tied directly into the single-player campaign story, it sounds like, but it will have some kind of unspecified effect on the single-player mode and its progress (just not in the main storyline).
Intriguingly, the multiplayer mode comes as but a single piece of a larger puzzle known only as "Galaxy at War." Playing around with the various aspects of this mode will allow players to augment Shepard's Galactic Readiness level, but again, will not directly tie into the main storyline, nor is it even required to get the game's optimal ending.
While we await more word on what all this Galaxy at War craziness entails, sit back and rest assured knowing that cooperative play awaits, and is totally optional. And if you were one of those people holding out for a 32-player Shepards vs. Shepards death match mode, take your sickness elsewhere and never come back. We don't take kindly to you types around these parts.