Anyway, recently I've started writing a story about a mermaid. It's set down south from here (Perth, Australia) in a seaside town called Denmark.I figured that it couldn't be called anything but fantasy and so I had no troubles (I usually don't like writing magic stories, but this one's just for a friend so I'm trying not to be over serious about it.) in throwing in magical abilities for the mermaid that she passes on to the boy she loves.

That's a good story, at least my friend thinks so far<grin>, that's not the problem. But now I've got all these story ideas I've been tackling. They had no sciencey elements in them when I first went back to them, and they certainly couldn't qualify as Space Opera (I think: They were on planet the wholse story). After this little taste of fantasy I've got from the mermaid story, I've been thinking up ways to explain major cultural things involvings the societies in the stories with fantasy. For example, one town needs a population of all young people (like no older than 17,18), so I have the older members leave as the come of certain age because dark things happen to the town the more people there are in it. (And with no-one over the age of 18~ it's a bit hard to overpopulate.)

Having these fantasy elements means they can't be science fiction, I reason, and I don't really know how to write fantasy. (The mermaid story was more contemporary with a very few moments of magic.) Should I go back and instead try and think of ways to make the stories sci-fi instead? Or else I need advice on fantasy writing.

This might not make sense. (I've only slept 4 hours in the last 42) If that's the case, tell em and I'll reword it when I've caught up on my sleep. I won't be sleeping just now though because I'm designing/writng the small population story at the moment.

For example with the idea of small population idea:

Rule 1: The older you get, the more life-force energy a person generates.
Rule 2: A monster/demon/spirit only notice when the combined life-force energy is over a certain level.
Rule 3: A monster/demon/spirit only culls as a matter of survival, there by leaving behind future prospects.

And so on.

Once you have developed the fantasy physics, then you can apply them to the world.

As a result of the above rules an adult would have to leave the permanent village and begin wandering the world. At first they could travel together until their combined life-force energy become noticed. Eventually the adults would either die of old age, alone or become individually noticed.

The one I'm working on at the moment, for example, is split into parts (The first being 15,000~ words long) and within those parts it is also split by chapters.

You can try getting someone to volunteer by posting your first 13....good luck that way.

Usually, you can send your whole novel as a word.doc