Triune is set in the future, so we need to describe how the future looks and works in our game books. But where do we stop?
A fantasy rpg setting is pretty easy to describe. People already know what castles, horses, swords, and 10′ poles look like. Yes, you might have to explain what a bec-de-corbin is, or what the elven Council of Elders is all about, but for the most part, players understand the imaginary world wherein they’re killing and looting. No one wonders what peasants eat.
A science fiction rpg setting is more difficult. Some tropes are understood–rocket ships are rocket ship no matter what you call them–but the basics of life could be so different from now that they need some level of description. Are guns still guns? Maybe, but maybe not. Players need to know which version of the future has shaped the setting. Does a FutureGun have a stun setting? Is there money? Do Space Peasants eat Space Peanut Butter?
It’s impossible to describe a sci-fi rpg setting completely. Quite possibly that’s a bad idea anyway; GMs should be able to tailor the setting to their needs. Yet you cannot leave too much for GMs to decide, especially if it impacts the gameplay. Where do you draw the line?
Our line is this: define what players need to know to play the game. In Triune, players are police hunting down religious sympathizers and rogue angels and devils. Do they need to know how the future criminal justice system works? Yes. It’s part of their character’s purview. How authorities handle criminals is important to the PCs. Do they need to know what peanut butter is like two hundred years from now? No. It has no bearing on the gameplay (at least none that can be reasonably predicted).
Therefore, we will be describing gear that PCs will encounter, prayers they can use and face in the course of an investigation, underground movements they might fight, and more. As for Space Peanut Butter, that’s up to your friendly GM.