Valve has announced a new mode for Team Fortress 2 that pits Red and Blu against a common threat: robots. Set to launch Wednesday, August 15, the Mann vs. Machine (MvM) update will introduce a co-op component that tasks you and up to five friends with stopping swarms of robots from deploying a bomb in one of Mann Co.'s strongholds.

As with many horde-style modes, enemies will attack in waves and you'll be able to upgrade your weapons and abilities during breathers, though we haven't found any detailed information about what kind of upgrades will be available. If you survive the onslaught, you'll be handsomely rewarded with "incredible loot" -- again, no specifics here.

The robots will be largely modeled off existing characters, including melee-oriented heavies, a sniper equipped with a bow and another with a rifle that shoots jarate-coated darts, quick fix and uber medics, as well as a demoman and scout. There will also be special robots such as the bomb carrier who gains buffs as the rounds unfold, an anti-engineer suicide bomber dubbed the "sentry buster," as well as giant versions of the solider, heavy and scout. It's likely that more enemy types have yet to be unveiled.

As it often does, Valve geared up for the MvM announcement with an alternate reality game that was said to be its most difficult to date, involving roughly 5,000 separate pieces of data. The ARG was so "needlessly complex" that the developer was concerned it might stump players for weeks, but the community prevailed in a mere 12 hours. If you're interested at all, Rock Paper Shotgun offers coverage on the ARG while The Escapist has a nice write-up on the goofy in-game lore behind this week's event.