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.

Today we have released a pretty big update for Left 4 Dead 2 that includes map bug and exploits fixes. The complete list is here.

These changes will be coming to the Xbox 360 with the title update that will accompany Cold Stream’s release. Before we send the game off to certification, we want to test these fixes on the PC. So please, give these maps a play through and tell us what you think.

The Cold Stream DLC will include 21 maps in total - the Cold Stream, Blood Harvest, Crash Course, Dead Air, and Death Toll campaigns. Besides the massive amount of new content, 360 users will also be getting many of the bug fixes and changes we have implemented since the last update.

We don’t have a release date yet, but we will make sure to post the minute we do.

Last Man On Earth
You will become legend to the infected as the last human left.

You are the only Survivor left in the world. No split screen help. No Survivor bots. But don't worry you aren't entirely alone. While there are no common Infected, Special Infected will hunt you down and become close, close friends with you.

Loners?
While the first part of this blog post should make the results of our last poll obvious, the second place finisher is just as interesting. Between Lone Gunman and "scared to play alone," seems about 30% of you are "scared to play alone" – putting that choice in second place. With that being true, today is a great day to overcome that fear and play Left 4 Dead 2 alone with Last Man On Earth.

After all, it is Friday the 13th, what could happen?

Versus Survival
The first Survivor team sets the time. The second team tries to beat it. Then the first team tries to beat the second team's time. Then the second team tries to beat the first team's time. And then the... you get the idea. Rounds keep switching until someone fails to beat the previous time.