"Rainbow Six Vegas 2 is an installment in the Rainbow Six series. It is a tactical first person shooter video game and the sequel to Tom Clancy's Rainbow Six: Vegas...
The game, billed as "part sequel, part prequel", has events that run both before and concurrently to the story of Logan Keller and continue after where the first game concluded. In addition to the ability to customize a character in multiplayer, the player can now customize Bishop, Vegas 2's protagonist. In single-player, the developers claim to have vastly improved teammate AI, so that now teammates cover each other as they advance. There are also several new commands, for example, the ability of a teammate to throw a grenade at a specific point. It is also possible to give commands to one's AI teammates using the Xbox 360 or Playstation 3 headset.
Source: Wikipedia, "Rainbow_Six_Vegas_2," available under the CC-BY-SA License.