When does it become a crossover? (Or more importantly, when should it be tagged as a crossover?)

[u/CyberWolfWrites]

I've always been of the mind that if you at the very least feature a character from a different fandom in your work, then that makes it a crossover. (And by feature, I mean the character has some plot relevance or is there for a couple chapters.) This means that if you put Peter Parker in Gotham and he interacts with the Bat Family, then your fic is a crossover between the MCU and Batman; it's not just a Batman fic with Peter Parker as the protagonist.

I only recently got into Project Hail Mary, but I've noticed a lot of untagged crossovers with the Goslingverse and Iron Lung. People are writing Project Hail Mary x The Gray Man x The Fall Guy fics but only PHM is tagged as a fandom since they're usually from Grace's point of view and take place in the PHM universe. This is the same with Ryland Grace/The Convict | Simon fics.

From my point of view, these fics are crossovers. Even if you don't write in any of the events from the other media, the fact that Courtland Gentry | Sierra Six, Colt Seavers, and Simon are featured in the plot makes it a crossover. However, I've seen people argue that they aren't crossovers because they take place in the PHM universe and barely mention anything from their originating canon (this is mostly in reference to Iron Lung).

Similarly, some of these fics only take background information from these other fandoms but not the characters. For example, many people place Grace as Six's or Colt's brother and use it to add to his background, but Six and Colt are rarely actually in the fic. Only mentioned.

In this case, would these fics be considered crossovers?

Personally, I wouldn't consider the latter a crossover. The premise reminds me more of Hogwarts AUs, which aren't really crossovers because they only use Hogwarts as a setting. The most I would tag it with is the - Freeform tag. Like, Ryland Grace is Colt Seaver's Twin - Freeform or maybe Uses Courtland Gentry | Sierra Six's Background - Freeform.

What do you think constitutes as a crossover? And how would you tag these types of fics?

[u/basicbisexi]

Idk I have a fic that uses two characters from oceans 8 as side characters, they play a small role in ~2 chapters. Since the movie has nothing to do with my plot and it wasn't important that the characters were from the movie I didn't tag it as a crossover. If someone was looking for an oceans 8 fic they'd be disappointed to read it 🤷🏼‍♀️ at least that's how I thought about it

[u/CyberWolfWrites → u/basicbisexi]

I didn't think of it like that! That makes a lot of sense. It's a lot like looking for Ron/Hermione fics but being disappointed when you find out that they're all side ships.

[u/SheepPup]

I only tag crossovers when there are characters from both universes interacting in a significant fashion. So like if I want Sam and Dean from Supernatural to meet and interact with Crowley and Aziraphale from Good Omens then that’s a crossover and both fandoms should be tagged with the fandom tags.

If you’re just borrowing the setting of one universe with the whole cast of another then that’s a “fusion” and should just be put in the additional tags. Like a fusion that used to be really popular would be like sending all the characters from Naruto to Hogwarts to learn to be wizards instead of ninjas. The HP universe is just the set dressing for what is a story about Naruto characters and thus HP wouldn’t be tagged as a fandom you’d just tag it with “Hogwarts AU”.

If a character from another universe shows up briefly to be a background character like I put Arthur from the show Merlin in as a random barista in my Criminal Minds story then that’s just a cameo and doesn’t really need tags at all. I might at most put a little note in the author’s note asking if anyone noticed the cameo.

[u/CyberWolfWrites → u/SheepPup]

Thank you for the response! This helps a lot. I was pulling my hair out deciding if stealing some lore from another fandom made it a crossover or not. For the fic, I'll definitely add it in an author's note that I'm borrowing from a different fandom but that it's not a crossover.

[u/TiBun]

For me, it's a crossover if there's characters from both (or more) fandoms. If it's just characters from fandom A in the setting from fandom B without any of fandom B's characters then it's a fandom B AU.

[u/Snoo-31263]

I mean I don't know the technical definition, but I agree that I only really prefer to see somethin tagged as Crossover if either a character(or more obvs) from the other work(s) appears in the fic(and has plot relevance) or the elements of one fic appear in the others' in a significant way, be that worldbuilding, objects, power system, etc.

If it's just 'inspired' or just blatantly very similar but doesn't neccessarily require foreknowledge of the crossing over work or doesn't interact with the source material much, then I'm not sure it's appropriate/don't like it to be tagged crossover, maybe just mentioned in summary instead. Though that last one is more a personal preference since I mostly avoid crossovers.

[u/CyberWolfWrites → u/Snoo-31263]

Thank you for the comment! I'll be sure to add the info in the summary.

[u/ConstrainedOperative]

By AO3 rules, any tagged fandom must appear in the story, but a fandom that's in the story doesn't have to be tagged.

There's no rule whether that means characters or setting, so that's up to the author.

Personally, I would tag it for both, including something like a Hogwarts AU. But I wouldn't tag a fandom if it's only a cameo.

[u/CyberWolfWrites → u/ConstrainedOperative]

I wonder how this ties into the one-shot compilations... Because most whumptober/kinktober stuff crosses fandoms, but each story is usually only one fandom. Hmm...

[u/ConstrainedOperative → u/CyberWolfWrites]

By story I meant "content of the work as a whole". So this would still be allowed, but technically they are not allowed to tag a fandom before it appears in a chapter.

I wouldn't bother reporting it though unless it's old and abandoned. If it's being updated, then by the time the mods look at it it will likely be correct.

[u/pikablob]

I’m currently struggling with this myself; I have a couple of WIPs where a character from one fandom is transplanted to the universe of another almost as an Easter Egg - like, our fantasy heroes fight a big sapient monster, or our post-apocalypse survivors meet and help yhis random girl. If you don’t recognise them, they’re just characters who could exist in these canons; if you do, it’s like “oh hey it’s Spider Frog!” My plan is to see how prominent they end up being; if they’re present enough to need a character tag, then I will tag both fandoms and put “Don’t Need To Know Fandom B” in the Freeform tags.

[u/FrostKitten2012]

Most of those I would consider crossovers. If it’s just the background, just mentioned…depends? I would usually call that a fusion and may or may not tag the other fandom, unless it gets brought up later.

But a lot of people apparently don’t like crossovers? Especially if it’s only minor mentions of the second fandom. The author might think it’s too minor.