How quickly does the fantasy need to be introduced?

[Tecdavid]

I think this is one of those things that when handled correctly, can really add a sense of tension and surprise. Just a trickle of fantasy in an otherwise plain-faced setting can catch people's curiosity, before the story begins to open up that fantasy for real. If the first few chapters have very little fantasy, then I'd say that's fine -- it allows you to introduce the characters and mood first, if you want.

The first seven chapters of my WIP are set in a "mundane" world -- a city as ordinary as any in this real world of ours. But a few things happen, curiously and sparingly. Like teasers for what's the come later in the story. And these "teasers" weigh on the characters' minds. They're mysteries to them. So it's just a trickling amount of fantasy to begin with, but it still holds some weight to the story, and yet it never reveals too much. (At least, I hope this is what I've achieved.)


So I’d say you can skimp on the fantasy as long as you like, just so long as you make good use of the fantasy you do reveal, and keep things interesting.

 

[James Coote]

I'm with allmywires on this one. subtle and in your own time.

I've read a lot of UF manga and they usually have a prologue to act as a film trailer: Lots of action and excitement revealing hints of what is to come without giving too much away (it usually happens at night). Then off to high school to meet our plucky hero in chapter one and the hint linking him to the prologue by the end of that chapter.

Not read much alternate history, but I imagine they have a similar balance to judge