It took nearly 20 years for a secret about Left 4 Dead 2 to finally be revealed. In a recent statement, Chet Faliszek, a former writer who worked at Valve, discussed the conflicts between the American company and the ESRB.

At the time, the U.S. rating board was putting obstacles in Valve’s way. This was due to the profanity, violence, and even the promotional poster for Left 4 Dead 2. The regulator had even gone so far as to block the release of a trailer. However, Valve found a way around this to publish the video in question.

"As for Left 4 Dead 2 and the ESRB… we leaked our trailer early because they wouldn’t let us release it.

You have to remember… Valve was in fights with the ESRB, with Australia, with Germany, with a bunch of countries about the profanity in the game, the violence.

I’ll just admit that [we leaked the trailer]. I think we can’t get in trouble for that now. It’s like 20 years ago."

Thus, Valve was not held responsible for the unofficial release of the trailer. Left 4 Dead 2 reused these images for its intro and received an M rating for “Mature” (restricted to players 17 and older).