A fan on the Tomb Raider forums has written up a bullet-pointed summary of the multiplayer details provided in February's issue of Official Xbox Magazine. According to “miss.haggard”, there are likely at least three modes: Team Deathmatch, Rescue, and a hinted “Cry for Help” mode. Lara didn't feature in any of the multiplayer shown to Official Xbox Magazine, presumably because ; instead players can pick from a “deep roster of characters”.
Team Deathmatch is fairly obvious, with some of Lara's surviving allies making up one team, and some of the hostile natives (apparently called “scavengers”) making up the other. The mode will be in a best-of-three form, with players alternating between the two sides.
Rescue has survivors collect med-packs and take them to various destinations, while the “scavengers” have the task of hitting a particular kill count. In the Rescue mode, survivors will have a “bleed-out” time, which can be cut short with a “brutal” melee finisher.
The hinted mode “Cry for Help”, is said to have “a strong emphasis on discovery and collection”, with less of a focus on combat.
Aside from that, no other modes are mentioned, though more may be available. The staff at the magazine played on a map called “Wind Chasm”, which “miss.haggard” describes as “tropical, with traps, vantage points and junk”. More maps will undoubtedly be available, potentially with more added as DLC.
So, it sounds much like the multiplayer in other games. Are you disappointed? Or happy that Tomb Raider is sticking with a formula that has worked for other games in the past?