First, let’s distinguish between fantasy stories set in what is basically our own world, and those set in different worlds. A fantasy set in our world can leverage existing settings, cultures, languages, etc. This simplifies some aspects of the writing process, but can add complications, particularly if set in the modern era. But it’s the other type I want to discuss.
Tolkien’s Middle Earth is the iconic example of a fantasy set in a world that is distinctly different than ours, but still has many similarities. There are different races, different languages, strange monsters, and powerful magic, but the world itself looks much like our own in terms of the flora and fauna. The technology level is medieval, with castles and keeps and walled cities. It’s swords & sorcery, in modern terms. Many fantasy novels hew to this pattern, including my own.
It is certainly possible to write a fantasy set in a completely different world. The world can have a green sky, ten moons, and three suns. All of the animals and plants can be different. There can be unique races, each with differing language, titles, units of measure, religion, magic, culture, government, etc. But unless the author is incredibly talented, I can pretty much guarantee it will turn into a confusing mess for the reader. I know, because I’ve read both fantasy and science fiction novels that have taken things too far. The reader needs something to identify with, and they don’t want to be constantly having to look things up in appendices.
Dungeons & Dragons was heavily influenced by Tolkien, and my world was based off of my own D&D campaign. That provided the basis, and I made a deliberate decision to not make any drastic changes. Medieval fantasy worlds of that kind are traditional now. The familiar elements comfort the reader and make it easier for them to imagine what is being described. And the magic and fantastic creatures thrill them, or so the author hopes. It certainly seems to be working for George R.R. Martin.
In a future post, I may discuss the specific decisions I made, and some of the unintended consequences that resulted. Happy writing.