If you’re writing fantasy, and especially fantasy novels, you’ll want to devote some serious attention to world-building. If you google “fantasy novel world-building,” as I did this evening, you’ll find any number of blog posts that will offer suggestions. Some of the suggestions you’ll encounter are very good, and there’s no need to rehash them here.
At a certain point, though, the online advice starts to feel a bit generic. Draw a map. Think about food production. What sort of government does your world (or nation, or region) have? Yes, of course — all that is important. But a few other questions are perhaps more basic, and they don’t seem to get quite so much attention.
Why are there humans in your world? That’s the first question that begs to be addressed.
If you’re writing science fiction and the setting is not our Earth, you have an easy answer: They traveled from our world to your imaginary world in interstellar space ships. (Creating plausible physics for interstellar travel is really a very awkward challenge, but let’s not get into that just now.) In a non-Earth fantasy, however, where do the humans come from?
Maybe they came from our Earth via a magical portal. That’s one possibility. But if there’s no portal — if the humans are indigenous to your world, as is quite often the case — the whole question of species evolution is going to leap up from a ditch and attack you with a cudgel. Where are the other primate species? Where are the ruins of the first cities that arose in the local Neolithic era? Are there cave paintings? Human history on Earth is an immensely complex pageant.
Okay, you’ve got your humans. But what about the dogs, the pigs, the horses, the butterflies? The potatoes and barley and trout? Many writers simply grab the entire biosphere of Earth and transplant it into their fantasy world, perhaps adding dragons to the mix but otherwise leaving everything in its well-known state. This is certainly a viable strategy when you’re writing (and hoping to sell) a book, but once you start to think about it, the oddness will creep up on you.
I don’t have an answer; I just think this is an interesting question.
Here’s another: seasons. Our own planet has what is probably a rather unusual axial tilt, on account of which there are summers, winters, and in-between seasons. Many fantasy novels have winter in them, but winter can’t quite be taken for granted if the planet isn’t Earth.
Are the years 365-odd days long? If not, the ages of your characters will have to be rejiggered. “He’s a full-grown man: He just turned eleven.” Your readers are bound to get confused. Are the days 24 hours long? There’s no particular reason why they should be. But making the planet too unlike Earth is likely to confuse readers. There’s a reason why terms like “hour,” “mile,” “bushel,” and “pound” are bedrock. They save the writer from having to provide detailed and boring explanations.
You can’t use kilometers and liters, by the way: The French invented those measures, and not very long ago.
Cultural artifacts can trip you up. I was quite distracted in the first book of Guy Gavriel Kay’s Fionavar story when one of the Canadian lads (who had arrived in Kay’s other world through a portal) sat down to play a game of chess with one of the locals. Putting horses in your world is one thing, and things like coins and swords are likely to be found in one form or another in any human culture — but chess is as fully a cultural artifact of our own Earth as the kilometer. Even here on our Earth, there are many different sets of rules for chess, most notably the Chinese and Japanese versions, which are quite different from the European version. How did Kay’s fantasy culture acquire specifically European chess? Through sloppy writing, that’s how.
You probably don’t want to try to create a whole world from scratch. It would take too long, and readers wouldn’t have the patience to wade through your explication of every detail of the fantasy biology. So go ahead, use horses and dogs. Nobody will mind. But be careful. Be aware of the assumptions you’re making. And do think about how you might be able to add a few unexpected details so as to make your imaginary world a bit fresh.
Dragons are not fresh.