Board Thread:General Discussion/@comment-36624593-20181205013841/@comment-32182236-20181209205218

Alright, since we don't know Deltarune's relationship with Undertale, how about we analyze it logically, shall we?

So first, we know that the world of Deltarune is not the world of Undertale. So any possibility that places them within the same "world" is already false.

Next, we have "different characters, who have lived different lives." Seeing as the characters are technically different, we can't call it a plain old alternate timeline, else the characters would actually be the same. So it's not a prequel or a sequel, in any way. Not only that, in the world of Deltarune, determination is not what allows one to SAVE and LOAD-It's the power of "shine" within you that does this. Further evidence that it's not DT doing this is that the save points are no longer yellow. The Manual (only in the demo) stated save points were the manifestation of your determination. The fact that this changes means the world's laws are different. Alternate timelines can't explain that. Not only that, the player is separate from Kris, and the player controls the SOUL. The SOUL was made artificially. Entry 2 in the True Lab states that SOUL power CANNOT be produced artificially. Once again, the laws are different.

Now, if we want to find out whether or not it's an AU, we first need to find out what an AU even is. There's two main definitions of the term, but only one can actually fit the current topic.


 * A hypothetical world situated in a different dimension of space and time than the real world consisting of the universe known and experienced by human beings.

This one is meaningless:All fiction would fit this definition, and if we use Undertale's frame of reference rather than our own, it's still completely meaningless, as it basically asks whether or not Deltarune is a hypothetical world in the realm of Undertale. ..Of course it is. Technically, our world would fit that too. And, well, any game's world.


 * An imaginary realm, often a variant form of the real world, depicting a different way events could have unfolded or the universe could have functioned.

This is more specific, which is why fanfiction uses this one rather than the former one when determining whether to call a work an AU or not. and, well, Deltarune almost certainly fits this definition as well. You see, the characters of Deltarune fit the personalities of those of Undertale's very accurately. This is no coincidence. Not only that, we have the same Delta Rune, and the laws are very similar, but not quite the same. The characters are similar.. not quite the same. It's a different way the world of Undertale could have worked.

--Conclusion--

Yes, Deltarune is an AU. Toby didn't say so, but from what he did say, and what we see in Deltarune, it can be said that it is indeed an AU. It can't be Undertale's world, it can't be an alternate timeline, and it can't be original fiction, so by process of elimination, it must be an AU-That's the only possibility that remains.