Writing a LitRPG or system novel

LitRPG readers are, in the nicest possible way, auditors. They will notice that a skill cost 40 mana in chapter twelve and 25 in chapter ninety, and they will say so. The craft problem of the genre is not inventing a system — that is the fun part — it is holding one consistent for longer than you can remember it.

The numbers are prose

Worth being clear-eyed about what a status window is: it is text the model writes because you asked for it, the same as a description of a room. That cuts both ways, and both are worth knowing.

In your favour: you have complete freedom over the system. No schema constrains what a stat means, no engine refuses the interesting exception, and a system that changes shape halfway through the story because the plot demands it is entirely available to you. Systems designed to satisfy software are usually worse than systems designed to satisfy a scene.

The cost: consistency is authored, not computed. Nothing adds up your protagonist's stats for you. So the discipline below is not busywork — it is the whole job.

Write the system down where the writer can read it

The story bible has three entry kinds that exist for exactly this:

• Concept — the rules themselves. How levelling works, what mana is, what happens at a class-up, why the system exists at all. One entry per rule, not one entry called "the system".
• Technique — every skill, with its cost and its limit. The limit is the important half; a skill with no stated cost drifts, because there is nothing to drift against.
• Item — anything with a number attached to it.

These are written as you accept chapters, and the writer reads them before scenes that involve them. That is what stops chapter ninety contradicting chapter twelve — and when it needs the exact wording of something, it searches the chapters themselves.

Design the system so it is possible to be consistent

• Shallow ladders. Ten levels you can describe beat a hundred you cannot. Every rung you add is a rung you have to keep straight.
• Gate on scarcity, not on arithmetic. "He cannot learn this until someone teaches him" is enforceable by a story. "He cannot learn this until 4,000 XP" is enforceable only by bookkeeping.
• Round numbers, few of them. If a status window has fourteen fields you will stop printing it by chapter twenty, and readers will notice that too.
• Decide what the system is for. A system that only measures power is a scoreboard. A system that costs the protagonist something — memory, sleep, name, years — is a plot.

In the premise

A dungeon-delver in a world where the System is a bureaucracy: skills are licensed, levels are taxed, and the interface she sees is an appeals form. Levelling is fast; paying for it is not.

Note what that premise does — it fixes the tone of every status window before one is written. The premise is read on every chapter, so a convention stated there holds without being repeated.