Power systems: designing costs and limits

The question that decides a power system is not what the power can do. It is what the power costs, and what it can never do. Brandon Sanderson's Second Law is the compressed version: "Limitations > Powers". What makes a system interesting is not its capabilities but its flaws, limits and costs, and the essay that states the law also insists on its status: "none of these 'laws' are absolute". It is a default that works, not a commandment, and the strongest counterexamples are stories that break it knowingly. What follows is how to be in that second group.

Why limits outrank powers

A power with no cost is a plot decompressor: every tension the story carefully winds, it unwinds in one paragraph. If the hero can teleport, no separation is final; if healing is free, no injury is real; if power grows without price, no victory costs anything the reader can feel. Limits restore pressure. The moment the reader knows teleportation is impossible, or burns a year of the caster's life, distance becomes a storytelling tool again.

Sanderson's own framing is worth taking literally, because he extends it past magic: the laws are "actually all principles of good writing, not just writing as it pertains to magic systems", and "Limitations are more important than abilities" is as true of characters, politics and detective work as of spells. A detective who can read minds has no mystery; a merchant who cannot fail has no story. The law is about scarcity, which is the raw material of plot.

Three kinds of restraint, three dramatic jobs

The essay distinguishes three things writers tend to blur, and they do different work:

1. Limitations are what the power cannot do, full stop. Fire magic that cannot work over water. They shape plot structure: whatever the limit walls off becomes the territory your story lives in. Politics, journeys and sieges exist mostly where the magic cannot reach.
2. Weaknesses are what an enemy can exploit. Sanderson's example is kryptonite: not something Superman cannot do, but something an antagonist can aim at him. Weaknesses create tactics and villains smart enough to use them.
3. Costs are what the user pays each time: effort, materials, time, lifespan, sanity, standing. His other example is the One Ring, whose cost is paid in the user's nature. Costs create arcs, because a price paid repeatedly changes who is paying it.

A finished system has all three, and knows which job each one is doing. When a climax falls flat, the diagnosis is usually a missing restraint rather than a weak power: nothing the scene needed to be difficult was actually difficult for this character.

Costs at progression scale

Web fiction leans hardest on this, because progression systems are escalation engines. In progression fantasy, cultivation stories and LitRPG, the character's capabilities rise on a schedule the reader can feel, and if costs do not rise on the same schedule, tension decays chapter by chapter until only the status screen is still interesting.

The working rule is that costs must scale with power. Early costs can be fatigue and scarce materials; late costs should be things the character cannot afford to lose. The best costs are paid in the story's own currency: memory when the magic is about memory, years of life when the story is about mortality, bonds when the story is about what power does to relationships. A cost the reader can picture is a cost that can carry a scene; a cost that is only a number on a sheet carries nothing.

Write the restraints down as world rules

Costs and limits are world rules in their purest form, and they need the same record-keeping: the statement, where it was established, its scope, and its exceptions. Two fields deserve special care. The reader-knowledge flag matters because a cost shown on the page is a promise the story renews every chapter, and the exceptions field matters because escalation pressure at chapter eighty is exactly when a writer most wants yesterday's limit to quietly move. A rule that changes should change on the record, in front of the author, with the chapter that changed it. That is the difference between an evolved system and an eroded one (see Sanderson's laws for the wider framework and Magic A is Magic A for why an unexplained violation reads as a hole rather than a development).

How Kanonara approaches this

Costs and limits live in Kanonara as world rule records with their evidence, and skills and character states carry their own history. When an analyzed chapter uses a power in a way a recorded rule forbids, or pays less than its stated cost, the check surfaces both passages, and the author decides whether it is a mistake, a hidden exception being revealed, or a rule whose time is up.