Stories are about people, and people are as incredibly complicated as the world they inhabit.
One of the things I like least about speculative fiction is the tendency to oversimplify. How many science fiction stories have you read that center around a monolithic water world? Or a forest moon? Planets have forests and water and everything else besides. It gets worse when we deal with cultures. Warriors races and simple pastoral people keep cropping up across the SF landscape.
Take a look at my beloved Coast Guard. It’s not monolithic. We’ve got law dogs and cuttermen and SAR types and airdales and divers. We’ve got the “Oorah” Coast Guard of the PSUs and the “Hard Hat” Coast Guard of the M-Pin world. Each of these groups have their own vocabulary, protocol and custom. There are even communities within communities. Red hull and black hull cuttermen may tip their hat to men who’ve made their careers on white hulls, but the job is different, and with it, the culture. The groups are so different that they might as well be a different service sometimes.
George R. R. Martin grasped this in his depiction of the Night’s Watch. There are Stewards and Builders and Rangers, and a pecking order amongst them. They have their own pride and prejudice, and each man who comes to the wall dreams of one over another as fits his own reasoning.
Addressing the true range of human complexity is really hard. It goes hand-in-hand with the “show don’t tell” rule as one of those things that turns your tight 80k word manuscript into a lumbering 200k word behemoth.
But it’s also one of the most important things in giving the sense of resonance and transportation that’s so critical in speculative fiction. We’re already making stuff up when we write these stories, it *must* feel real if you don’t want to lose the reader.
Taking the time to address the layers of real life in made up worlds is hard work. But if you want to write a great book, you have to do it.