By the time Activision deployed the original Black Ops in November 2010, Call of Duty had already revolutionized online multiplayer. Alongside Halo 2, Call of Duty 2 in 2005 proved itself a must-play online experience for Xbox 360 owners, thanks to well-balanced gameplay and a variety of modes that weren’t even held back by the limited player counts on console. Treyarch's Call of Duty 3 multiplayer raised the stakes one year later despite tepid reception at launch, having introduced its console-only audience to revelatory features like the multiplayer class system and grenade cooking. Larger maps and vehicles debuted in the 2006 chapter as well, though nothing could hold a candle to what came next in the fourth mainline title.