What is the difference between young adult and adult fantasy?

[SineNomine]

Aside from, as mentioned, the general tone of voice used from the perspective of the main character, I would've said "Length" in the past though obviously that barrier has been broken down somewhat. However, in general it remains true that YA books average much shorter lengths than adult novels. You're going to have a hard time selling a YA book over 80k or so words. You can definitely do it, but you may have to fight for it and accept that both agents and editors will want you to chop it down to that size if at all possible.

 

[Chessie]

^^ Why so negative? Selling books is difficult but there's a thriving market for YA.

I recently finished reading a YA fantasy novel. It was 291 pages, with simple writing and just enough detail to keep you informed. It was all right but the difference between it and adult seemed to be life themes. Could just have been the author's preference but the only kiss in the book was one on the cheek and even that was a big deal. Everything seemed toned down. Definitely not my cup of tea.

 

[Ophiucha]

I don't know, Opiucha. I don't things are as clear-cut as they used to be. For example:

(spoiler tags for language)

Spoiler: Language

I read a YA fantasy where one girl comes upon another giving a boy a blowjob in the halls of their school. The characters are sexually active, and discuss sex, sometimes in explicit language. In Pretty Little Liars, Aria (who is supposed to be sixteen) is having an affair with one of her high school teachers, which brings up consent issues as well as teacher-student ethical issues (and the relationship is romanticized).

Other YA novels deal with hardcore drug use (meth or heroine in the one I am thinking about), and sexual favors that amount to prostitution to obtain drugs. They deal with rape, suicide, murder, mental illness, and just about any other subject you can think of, and it's not all sanitized.

Teen/YA readers engages in sex (some of them), some do drugs, many more are affected by drug use. They curse and use explicit language. I think that's all fair game in YA novels these days, from what I've seen. Certainly, any given reader (or her parents) might object, and as you said publishers will have their own ideas of what is suitable or not, and that will vary from publisher to publisher. But as for subject matter, even when more graphically depicted, being off the table, I'm just not seeing it.

Ha, yeah, I certainly know teenagers engage in quite a bit of that - I'm only 21, it wasn't that long ago that I was a teenager myself. But it was also not that long ago when the majority of what my friends read was YA fiction, and... yeah, there are exceptions to any rule, but they sort of have to be relevant to the plot/themes of the novel. Like, a story could be about slaying dragons and seducing vampires but still feature casual cigarette smoking and underage drinking and a little mary jane. But anything harder? It's rare to read a book about those drugs which isn't explicitly dealing with drug addiction, drug use, someone dying from overdose, etc., etc..

Presuming it's anything like the TV show, Aria's entire storyline basically revolves around her romance with her teacher.

In the context of YA fantasy, it is very rare to see these issues tackled because the plot of the story is almost always about fighting some evil organization or collecting a bunch of macguffins or choosing which sexy supernatural beast to sleep with. 'Adult' issues can be tackled in YA, but they almost always have to be the focus of the novel in order to work. Like with non-white and LGBT characters. There are entire subgenres dedicated to those stories, about racism and homophobia/transphobia, but YA fantasy doesn't tend to tackle them because those are 'heavy' issues that kind of get in the way of the dragon slaying. Which is sort of silly because you don't have to tackle those in every story about gay/black/whatever people but that's a different rant.

It's kind of nuanced and is more context than content, but there are definitely lines that can be crossed.