@sphennings Got it, good clarification. I see where I'll need to set the rules in now. I know where the beats are and when the allusions need to happen, so yeah - I see now that I haven't committed to the "crunch" because I haven't written it out yet. I do think the reader will get an idea of what's possible before I show the next layer to it.

@ThomasF.Webber You don't necessarily need to write out the crunch, but you will want to have an idea of the capabilities, separate from how you describe it.

Fluff and originated in tabletop gaming to distinguish between the flavorful descriptions and backstory, from the game mechanics.

You want to make sure that your fluff and crunch agree with each other, otherwise a game will have ludonarrative dissonance. If your soldiers with the most technologically advanced weapons in the galaxy have the same weapon statistics as the ramshackle weapons of a bunch of primitive marauders people will notice how the narrative contradicts the mechanical reality.

Another useful rule in any fiction writing is "show don't tell" with magic this can be that instead of describing in great detail and length exactly how the magic works in a series of large info dumps, just show people using magic. Note how Gaiman's wizard duel doesn't explain anything. You get to watch it play out and get a narration, not about the rules of the duel, or how forms are made manifest, but about how the duel feels to Morpheus, what he's thinking about as the stakes rise.