Left 4 Dead is going on a road trip this summer. If you missed the announcement, some of our common zombies made their way over to Counter-Strike: Global Offensive for the Zombie Mod.

Today, Team Fortress 2 is adding co-op and robots to their game! There is only one problem - don’t worry, robots are just the zombies of the future that’s not the problem – the problem is this is 6 player co-op not 4. So you’re gonna need to find a few new friends, a younger brother, your mom, someone, anyone to join you and your three friend to fight the lethal horde of robots.

Gib Fest
Blast the infected to shreds with M60s.

Swords can slice up some fun. Chainsaws can tear apart the infected. But you need to get close for both and well… chainsaws are really loud! Time to go with the ultimate gun, you and three friends armed with M60s and unlimited ammo. This is going to get messy.

Cold Stream is out for the Xbox 360!
For Xbox 360 players this is your first chance to play the 5 Campaigns contained in Cold Stream... We have all the details available on our Cold Stream update page at www.l4d.com/coldstream. Also With this update, you can now play any mutation at any time - just press the Y Button to cycle through to your favorites! (You need to own The Passing DLC for access to Mutations.)

Cold Stream Is Out!
For PC players, we have some map updates that move the big Beta needle to Release. For Xbox 360 players sorry but the Cold Stream DLC on the Xbox 360 is going to be delayed until next week.

We have almost all the details available here on our Cold Stream Update page – we just missed one – to celebrate the launch of Cold Stream – Left 4 Dead 2 is 75% off on Steam! Time to introduce some new friends to the Zombie Apocalypse.

Visit the Cold Stream Update page.

It has been too long since we had some stats, so we took a break today to run some numbers from yesterday’s (July 12th) activity on the PC.
237,412 Players played 7,147,979 minutes for an average session time of 30 minutes.

Nightmare
You’ll never see them coming

This Survival Mutation was inspired by Karma Jockey. There are commons, plenty of beefed up Specials, no glows, and lots and lots of fog. If you like to be scared by things that jump out at you from the night, this one is for you.

What do Zombies Think?
While cleaning/moving our offices around (all our desks at Valve are on wheels so we can have desk races), we discovered this old, long ago used Zombie decision making tree. It was created before our session with Mike Patton to record the common zombie sounds. While it is near indecipherable gibberish thanks to bad penmanship, it shows not at an AI level how a zombie behaves but all the speech opportunities and transitions.

Our favorite is the top. Lay Down? Nope. Want to vomit? Sure.

Flu Season
The smell of spit and bile in the air.

This Coop Mutation is a mashup of "Boomer Shooter" by SR69MMJC and "Spitters!" by Karma Jockey. The only specials are Boomers and Spitters. The only commons are the result of the Boomer. The only other change is we amped up everything about these two Specials. But don’t worry you’ll be okay as long as you avoid all the goo flying in the air.

PAX?
PAX Prime is taking place this year from August 31st to Sept 2nd. It is a great event filled with gaming and gaming culture. While the tickets have already sold out, we are curious to know how many L4D players will be visiting. So the question is simple – will you be attending PAX Prime this year?

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Follow the Liter, Infection!

Follow the Liter
Scavenge one can at a time.

No more fighting over what cans to grab first. This Mutation spawns only one group of cans at a time, so survivors know exactly where to go. There is only one problem: the Infected know exactly where they are going.

This presents a different strategy from regular Scavenge mode and actually tips match in favor of the Infected.