It's not that kind of multiplayer. There's no deathmatch, no CTF... MP is the same as single player... same story, same quests, same save file. You load up your character and jump into a single player game but with up to 3 other people, then off you all go to find the vault. The only thing that really counts as a separate mode is an arena you can go into if you fancy shooting at each other but it's hardly a full fledged extra mode.
