Location from Deltarune by Toby Fox
Alternate realities created by Dark Fountains — where real-world objects become sentient beings, Lightners become heroes, and the line between game and reality dissolves.
A Dark World is created when a Dark Fountain is opened — a geyser of dark energy that transforms a space and gives sentience to the objects within it. The Darkners who inhabit these worlds believe themselves to be real people with real histories, and they are — until the Fountain is sealed and they become objects again (unless they relocate to Castle Town). The prophecy says that if too many Fountains open simultaneously, the Roaring will occur — a cataclysmic event where the Titans rise and all worlds are consumed. The Knight keeps opening Fountains. The heroes keep sealing them. This is the game's central loop, and the question of whether it can be sustained is growing louder. Dark Worlds are where Deltarune becomes an RPG — the combat, the exploration, the party dynamics all happen here. Hometown is where it becomes a horror game.
Dark Worlds vary dramatically in appearance based on the real-world objects that form them. Card Kingdom is board games and playing cards. Cyber World is computers and the internet. But all Dark Worlds share certain traits: darkness at the edges, a Fountain at the center, and a quality of light that feels slightly unreal. They are vivid in a way that Hometown is not — brighter, louder, more saturated. Whether this makes them more or less real is the question.
Also known as: The Dark World, Dark Worlds