Valve's development excursions are always a grand mystery in the gaming community. Enough info leaks for fans of Valve's games to know that games like Half-Life 3, Left 4 Dead 3, and other titles were in the works, but not enough to know exactly what happened to them. Yet another example of this has been discovered care of Geoff Keighley's recent documentary on Half-Life: Alyx's development, wherein new details about Valve's canceled Left 4 Dead 3 project have been shared.

According to Keighley, Valve had very big plans for Left 4 Dead 3. Bigger plans than most people ever realized. Left 4 Dead 3 wasn't just going to be another iteration on the popular cooperative shooter format. Rather, Keighley says that Valve planned to make Left 4 Dead 3 into a major open-world game the likes of which had never been done before.

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While Keighley didn't expand on what being an open-world game would mean for Left 4 Dead 3, he did mention that it would enable Valve to potentially feature hundreds of zombies on-screen at a time. Days Gone managed quite a large number of zombies in its open world, though those zombies wouldn't aren't as clever as the ones known from Left 4 Dead. Dead Rising 4 also featured a lot of zombies in its open world, but not necessarily what Valve could have accomplished if it stuck with it.

The only other detail shared by Keighley about Left 4 Dead 3 is that it would take place in Morocco. There's no notable information regarding why Morocco was chosen, but it does coincide with several leaked Left 4 Dead 3 screenshots from early 2019 that showed a wide-open Moroccan map.

Ultimately, Left 4 Dead 3 was reportedly canceled due to frustrations with and the slow development of Valve's Source 2 engine. The now unfinished engine has been cited as the cause of several of Valve's modern canceled projects.

For the time being, Keighley says that Valve has a major secret project that it's working on since 2018. It's also said to be considering a major Half-Life game following the success of Half-Life: Alyx. There's no word on another Left 4 Dead project for the time being, as exciting as an open-world Left 4 Dead 3 could be.

Left 4 Dead 3 is a canceled project from Valve that's no longer in development.

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