When we build a world for our fictions, games, and shows, we construct cultures. Cultures explain why people do what they do, how they think, why they eat, how they war, how they make peace, and more. Culture is unavoidable when you make a setting – one could even argue that characters are often expressions of their cultures.
When we build these cultures we're often thinking about important things. We want to know why characters believe as they do. We want to explain why characters go where they go and do what they do. We want to explain why magic is the prerogative of the ruling class, why there's a different language spoken on this distant space station, and so on. We want to explain what matters – in short, cultures explain the Big Plot.
This is short-sighted.
Take a look at our culture and ask yourself, for a moment, how much of it is relevant to our larger "plots." How many ways of making food, clothes styles, and so on actually aren't that relevant? How many things that we do or say are just window dressing, or leftovers, or pointless to "the big picture"? A lot of our culture may not seem that relevant.
If you're creating a culture, and you want it believable? Then you better have a believable level of irrelevancy in it, of small details that may not matter to our big plots. Our own cultures do not reflect some One True Plot, so neither should the ones you build.
Consider such things as:
- Superstitions. These may not always be relevant to the plot, but may explain a lot about the culture, the characters, and just plain be interesting.
- Fashion. Sure sometimes fashion is relevant – and sometimes it's shallow trends. But it tells you a lot about the culture if there is fashion, and as we all know dressing habits may tell us about characters.
- Habits. How many of us engage in irrelevant habits that have nothing to do with, well, much of anything?
- Traditions. Traditions can be part of the Big Plot. They can also become fossilized and irrelevant, more explanatory or historical than being part of the story.
So next time you're world-building, take time for irrelevancy, strangeness, and other things that don't matter to the plot. Your world will be richer and more believable for it.