BioShock 4 has been in quiet development since at least December 2019, when 2K Games announced the creation of a new studio, Cloud Chamber, to continue the series. The last BioShock game released in 2013, so there might be some temptation for Bioshock 4 to return to the iconic setting of the initial titles, Rapture. That would probably be a mistake, however, for both narrative and practical reasons.
In the BioShock universe, Rapture is an underwater city created by Andrew Ryan, a business magnate looking to escape the control of governments and religion. Unbound by laws or conventional morality, Ryan and his scientists are able to infuse people with superhuman abilities in the form of Plasmids. Thematically, BioShock critiques the objectivist philosophy of Ayn Rand, so Ryan's utopia falls apart amid infighting and the unchecked capitalism and technology at play. The city is never fully destroyed by the end of BioShock 2, but it is implied that both its walls and the few people left there are doomed to collapse.
In of plot and gameplay, there doesn't seem to be much left to squeeze out of Rapture. Both Ryan and his successor, Sofia Lamb, are out of the picture by the end of BioShock 2, a game that already stretched the idea that Rapture could survive a civil war. The title didn't offer major gameplay changes either, perhaps for obvious reasons; a crumbling city cut off from the rest of the world isn't going to see huge technological leaps or many new characters, especially if most of the population is are violent mutants.
BioShock 4 Setting: Would You Kindly Go In A New Direction?
Philosophically, just about everything that could be extracted from Rapture has been. The first game pretty thoroughly debunked the idea that a city could thrive on selfishness, and BioShock 2 went the opposite direction, tackling extreme versions of collectivism. Perhaps a third game could see Rapture taken over by misguided centrists, fascists, nihilists, or anarchists, but those critiques could just as easily be done in another setting, as BioShock Infinite proved.
BioShock 4 is expected to feature an open world, which may offer the most obvious reason to avoid Rapture. Even if the game was set pre-war, the city wouldn't exactly be "open" - just a series of corridors and concourses with the occasional sub trip. Missions would probably be as gated as ever. BioShock 4 needs broader horizons, both literally and figuratively.
