DARK WORLDS

Basically, there are these things called Dark Worlds. They seem to be manifestations of objects and areas pasts, including the Dark World's creator's will, and have masses of lore based on the history of the area even if they had been created like an hour ago.

GOD I LOVE THIS LORE!!!!!!!! I LOVE HOW OPEN IT IS FOR NEW CREATIONS AND I LOVE HOW IT OPENS DISCUSSIONS ABOUT FUTURE DARK WORLDS!!!!!!!!

Dark Fountains

Most dark worlds are created by a being who is determined enough to make one, and strikes the ground with that amount of determination, as stated by Q5U4EX7YY2E9N and literally shown at the end of Chapter 2 with Kris making a new dark fountain.

Kris' determination could possibly be tied back to the save points, them having a previous save before the player at the start of a new game, considering the game is similar to Undertale, but that quickly gets shot down with the fact that we (the player) are controlling Kris' soul, and they created the dark fountain without the soul inside them, showing that determination in Deltarune behaves differently than in Undertale.

When the fountain is initially formed, it will take from the area's history and the area itself, which means parallels can be drawn from the room that the dark fountain is in, and the dark world it creates.

This is shown by the amount of similarities there are between the actual room and dark world, seen on the image to the right. eg. Cyber's Field has a similar colour to the carpet in the computer lab, the plug NPCs are the plugs in the walls, etc.

You can also see it in the old classroom after you seal Chapter 1's fountain and a the start of Chapter 2, but I don't have enough time or room to put a diagram of that on here, but its basically the same idea. Similar carpets, different darkners as objects in the room, you get the idea.

This also applies with the area's history, like with the backstory of the Lightners throwing the Card Kingdom to the side lining up with the fact that the classroom is very unused and full of dust at the time that Chapter 1 takes place. It also is apparent with Chapter 2's dark fountain, with the internet not working through the town, and Q5U4EX7YY2E9N being upset about how the lightners aren't using the internet or something like that.

Darkners

I want to preface this by explaining the text box differences between Darkners (being of the Dark World) and Lightners (beings of the Light World).

DARKNERS HAVE COLOURED TALK SPRITES WHILE LIGHTNERS HAVE MONOCHROMATIC TWO-TONE TALK SPRITES

sorry for the emphasis, its just i sometimes see people with Ralsei/Asriel theories and they completely disregard the fact that in the light world darkners are objects which was already discovered/theorised when only chapter 1 was out, and the fact that ralsei is pretty obviously not a lightner because of his very coloured talk sprite.

Anyway, as stated before, darkners are the manifestations of an object's history as a new being called a Darkner. They can only exist in their own dark world, and leaving that dark world for another will turn them to stone. Thats probably because of the 'dark worlds being reflected from the creator's will' and some other stuff about them not fitting in the world.

They can have similar abilities to people from the light world (like Kris, Noelle, Susie), however