This is a commonly asked question! As we know, during the beta it was 6v6 But there was many other game modes left Locked. So unfortunately we dont know at this time what other game modes will be supported. HOWEVER!!!!!!! way back during the Game Developers Conference, something similar to this was asked involving customizing games maps etc. And Bungie's Mark Shepard responded along the lines of ( paraphrasing not direct quote) " it is something we are interested in allowing the players to get their hands on and customize content/ game modes, But it is very far out if possible at all. " So with that lil tid bit, and Bungies history of allowing customize matchmaking ( customizable match making is required if a game is going to see MLG content) I would SPECULATE that, some of the other game modes, are NOT restricted to 6v6, and maybe have some 3v3. As for 2v2 and 1v1, im not so sure about us seeing at launch. But 3v3 i sort of expect to see. As far as 1v1 goes, i would like to see a "Duel" option o_O