In writing, especially writing epic fantasy worlds similar to what J.R.R. Tolkien has created, there’s a tendency for writers to want to paint a picture so perfect that they literally explain every single element of a scene in excruciating detail. Every piece of a setting is pinned down perfectly and every character described so well a hundred forensic artists could come up with the exact same sketch.
This kind of writing can be a lot of fun. A lot of the time, this kind of description is a blast for writers to do, not only because we love our own worlds and have vivid images in our own heads for what exactly they look like, but because they give us a chance to stretch our wings and really play with vocabulary and structure in describing things well. When I sit down to hash out a scene or experiment with a character, a big part of what I do is description because it’s fun.
However, this kind of heavily detailed description robs your reader from the chance to really imagine the world you’re creating. I mean, sure, he’ll imagine it a bit just by putting the pieces of what you’re saying together, but he won’t get the chance to really let his mind go crazy with what that means because you’ve set up rules that really limit what can and cannot happen. Basically, you want a balance between giving enough description to paint a clear picture and not giving so much description that the picture is in super-high def on an old TV screen.
There are some pretty big reasons you’ll want your readers to have a chance to imagine your world on their own, and here are a few of them:
They make it their own.
This kind of goes without saying, but when your reader gets to imagine a world his own way, it essentially becomes “his.” And when he makes it, it will stick more firmly in his head than the world in your head. Essentially, he’ll make it elaborate in ways that he remembers and feels comfortable in, rather than being put into your elaborate head. And this is because…
They fill in the pieces with things they relate to.
The pieces you don’t explicitly mention–maybe the tile in the kitchen or the color of the curtains–they’ll fill in with the things they like or the elements from their own lives. They’ll relate to a character more if they can imagine the character looks kinda like their father (which could be an awesome thing or not). Additionally, when you describe something as “welcoming,” they can make up what that means to them.
They’re less likely to get super bored.
This one depends on the people, since some readers really love to get inundated in complicated and dense language, but on average, most people would rather have a fun read than one they need to break out the dictionary for. The more complex the description, the more likely your reader is to get lost, bored, or simply stop caring (and they’re more likely to care if they have to use their own imagination to fill in the gaps).
Your reader is the single most important person when it comes to your work. Essentially, readers decide whether or not you succeed or fail. Additionally, readers are way smarter than most writers give them credit for, and if you give them gaps in detail to fill in with their own imaginations, you’ll probably be pleasantly surprised with the way they take it.