A lot of Fallout fans aren't too happy about the direction the newest game is going in. The upcoming Fallout 76, now in beta, is going to be an MMO. Bethesda did promise that Fallout 76 is more of an experiment than an indication of where the series is going as a whole, but it doesn't change the fact that the experience is geared towards multiplayer. Fortunately, those looking for a deep single-player story set in the Fallout world are about to get one, albeit from an unofficial source.
Fallout: New California is a project seven years in the making, a mod that transforms Fallout: New Vegas into a California-themed prequel game. Despite being the work of volunteers who are in no way officially associated with the Fallout franchise, New California will tell an original story set between the events of Fallout 3 and Fallout: New Vegas. Eurogamer reports that the mod contains 14,877 lines of dialogue voiced by 60 volunteer actors.
Players will once again assume the role of a vault dweller who steps out into the world after an event of mass destruction. This time it will be the war between the Enclave and the New California Republic. You'll start off in the San Bernadino Mountains, but will be able to explore a map "that's about two thirds the size of the New Vegas map." The story, depending on how much you explore, will take anywhere between six to thirty hours to complete.
Polygon writes that Fallout: New California will have 13 possible endings. It also notes that the mod was known as "Project Brazil" at one point. There was no problem changing the name to Fallout: New California until the official Fallout board game was released last year. The board game was successful enough to earn an expansion, also titled Fallout: New California. Apparently the team behind the mod was able to clear things with the company making the board game, and released the mod without issue. You certainly wouldn't see that with a Nintendo mod.
Fallout: New California can be downloaded here. Of course, you'll need a copy of Fallout: New Vegas.