One Valve employee accidentally posts a screenshot of his work desktop in an official tutorial without removing a clue to the existence of Left 4 Dead 3 first.

Rumors have swirled for months that Left 4 Dead 3 is in development, but nothing official has been announced by Valve thus far. Today, however, evidence that Left 4 Dead 3 is indeed under development has come to light from a leak directly from Valve.

Tristan Reidford is a conceptual artist working for Valve who made the mistake of not closely examining his screenshots before uploading them for the purpose of an unrelated Destinations Workshop tutorial. While the tutorial doesn't contain any materials or assets from Left 4 Dead 3, eagle-eyed gamers realized that Reidford had presumably overlooked the fact that one of his most-recently accessed folders was still visible in the screenshot. The folder in question is simply entitled 'Left4Dead3', leading many to believe that the artist is currently working on the game.

Adding further fuel to the fire that the folder was revealing something is the fact that it has since been removed from the tutorial. Though no official statement has been made by Reidford or Valve, the screenshot was quietly replaced with a nearly-identical one, with the sole difference being the lack of a Left 4 Dead 3 folder on his recently accessed file list.

In addition, gamers have analyzed Reidford's Steam profile and discovered that he has spent a lot of time playing Left 4 Dead 2 recently. While it's possible that he's simply enjoying some time in the co-op zombie shooter, gamers have speculated that something else may be going on. Despite the fact that Left 4 Dead 2 released over six years ago, the Left 4 Dead 2 beta is still receiving frequent updates. While nothing is known for certain, it's possible that the developers are using Left 4 Dead 2 to test out mechanics they want to include in Left 4 Dead 3.

Left 4 Dead 3 has been rumored for years, but stronger proof emerged last year that the game could actually be in development. In addition to rumors that Left 4 Dead will release in 2017, files hidden in Valve's VR performance test revealed a possible Left 4 Dead 3 survivor texture. However, if the game really is in development, Valve is keeping it tightly under wraps.

Admittedly, Valve has good reason to remain quiet about any upcoming games. They learned their lesson years ago when Half-Life 2 was leaked ahead of its release, so they probably have good reason to be cautious. Even so, it was disappointing that there was no sign of Left 4 Dead 3 during E3 2016. With any luck, another gaming expo this year will hold a big reveal from Valve - perhaps showcasing the first game they've ever made to contain the number 3 in the title.

Left 4 Dead 3 is rumored to release in 2017, presumably for PC, PS4, and Xbox One.

Source: Valve Time