Valve leaks Left 4 Dead prototype via a Counter-Strike update – Destructoid

Many of you will be aware that Left 4 Dead began as a mod for Counter-Strike called “Terror Strike.” However, it looks as though Valve accidentally released an early version of the former via an update of the latter.

In patch 1.6 of Counter-Strike, players noticed “Terror Strike” had been compiled, seemingly unintentionally, and released to the public as part of the update. A post from Twitter user Gabe Follower shows a brief clip from it, with a comment saying that it didn’t take long for the community to work out how to play it.

Indeed, a video from the YouTube channel ilovethevopo not only showed gameplay footage from this Left 4 Dead prototype, but made it available for download.

The basic pieces are all there

As you can see, it looks and plays like Counter-Strike, but with the addition of “zombies” as the player moves around the map. In Gabe Follower’s clip, when the player places the bomb down on the target, we hear the familiar Left 4 Dead zombie howl before they’re set upon.

During development, L4D was intended as a versus game, but some feedback from Gabe Newell and others at Valve soon saw it change into what we know today. Of course, versus mode is still there, but its four player co-operative mode was what made it stand out.

The game turned 15 recently and is still held aloft as one of history’s greatest zombie shoot-em-ups. While the likes of Back 4 Blood attempted to revive the dormant series by offering a spiritual successor, in the end it couldn’t quite match up to what Left 4 Dead fans were hoping for.