Universe B (The Jenny Everywhere Roleplaying Game)
A set of hermetic, shift-proof rooms existed in one universe. It was set up to endlessly pit teams of adventurers led by versions of Jenny Everywhere against one another: the only way to exit the complex was to have shifted a second team in and either beaten them at the trials, or gotten them to concede of their own free will, meaning that at all times there would be bound to be at least one team left in the complex who would have to shift a new team in if they wanted a chance to go home. The teams were collected by Robotic Insects with the ability to travel across dimensions to find their marks. (GAME: The Jenny Everywhere Roleplaying Game)
Behind the scenes
Since the characters never step foot outside the complex, it is unclear if the complex is simply a special building in a “normal” universe, or if there is no such thing as outside and the complex is a pocket dimension of its own.