For some of us in the historical society, questions about when to call something "Alt. Universe" have come up now and again.
So here I am with my own definite guideline for when it is appropriate:

To me, "Alternate Universe" should only apply when canon(aired or referenced) events and plot points are taken and altered.

Example:
(In alternate universe)
1000 years ago Nightmare moon defeated Celestia and encased earth in darkness.
(this is alternate because it cancels out the premise of the first two episodes and changes the timeline of the entire show because the world under Nightmare Moon would be different)
(or)
Discord was never released from the statue and so no one had to fight him.
(this is alternate,because it cancels out the first episodes of season 2,but without conflicting with any other part of the show. it would be an alteration that caused a non-conflict)

And that's it. That's my opinion.
Any change made to canon events for the structuring of narratives on the alternate outcomes is "Alternate Universe".

So for us history folks, insofar as our work doesn't conflict with canon events, it shouldn't count as "alternate universe". We can write anything about what leads up to the canon present and what may follow afterwards as long as there is no overt conflict with exact canon events.

what do you guys think?
does this work or does it derp?

285010
Personally, I think you are right. I think that Alt. Universe only applies when said events are changed according to canon. A story where characters travel to a seperate universe is not an alternate universe. That is an adventure. Though, if I had my way, there would be two universe tags. One for alternate universe, and one labeled "Multiverse". The multiverse tag could be used to label a story in which a character travels or ends up in another universe. that way, authors could more precisely allow their readers to tell the difference between their stories. What does everypony else think about my idea?

What about when a story is in the normal universe, but then the show canon contradicts it? Does the story move from being show-canon to alt-universe, or is it grandfathered in?

285033 You're trying to stick to the canon as best you can, so that wouldnt be alt universe. I mean, if deviation from every little fact created an alt universe fic, then that would make practically all fanfiction alternate.

Alt. Universe is a tag that designates the primary goal of the story. It is a deliberate deviation, and an exploration of events that would result because of that deviation.

285040
EEEXACTLY!

285040
That's very succinct and very, very correct. Alternate Universes only spring up when one deliberately changes something in the past, whether near or far, explicitly or implicitly.

Rule 63 stories, for example, usually involve the question "What if the characters had been born as the other gender, but still developed the same or similar personalities?", thereby changing events in the past, namely the characters' births. There are always notable examples, but I personally wouldn't consider them alternate universes; in the case of The 63rd Rune, it ended up being in canon universe, imo, as they started out as the girls, but a spell gone wrong changed them. Spells go wrong all the time.

Anyway, the examples cited, such as Nightmare Moon winning, are excellent cases for alt. universe. Might I suggest another one for the list? Ask Diane Pie took the alt universes on tumblr and challenged it directly: Twilight has Pinkie's personality and vice-versa. All this because Princess Luna had to defeat the evil Solar Flare. Granted, the blog itself relies heavily on elements from Homestuck, but the AU idea is solid. What if Luna hadn't been the one to grow jealous, but Celestia?

285010 I think it works. Unless it's a purposeful deviation that conflicts with canon, it shouldn't be classified as Alt Uni. My fanfic Canterlot: Her Creation and Her Architects is slightly twisting canon...(well just the opening scene in which it shows Canterlot built) I plan to rectify that by doing a side-fic at the end or during, tying back to canon.

Hold on... In the season 5 finale (Correct me if i'm wrong,) Twilight explores a whole bunch of split timelines. Would a fic in one of those be considered "Alternate Universe" or not? I mean, they are all alternate, but they're all canon as well... so...?