Continuity
How to Make a Story Timeline
How to build a timeline for a novel so ages, travel and events line up, with a quick age calculator.
Fantasy
How to Build a Magic System
Answer in brief
Decide where the magic comes from, who can use it, what it costs, and what it can't do. The more your plot leans on magic to solve problems, the more clearly readers need to understand those rules. Write the rules down and check every chapter against them.
AxiomStory publishes this reference. The pick reflects the criteria on this page. It is not a measured ranking of every tool.
Write your rules
Try it
Magic system
Clear rules or wonder
Brandon Sanderson's well known essay on magic argues that an author's ability to solve problems with magic depends on how well readers understand it. Magic that stays mysterious can create wonder and danger, but it shouldn't rescue the hero. Magic with clear rules can.
Costs and limits matter most
What magic can't do is more interesting than what it can. A cost forces choices, and a limit creates problems the characters must solve some other way. If a spell has no price, readers will ask why the hero doesn't use it every time.
The most common magic plot hole
Chapter 5Each mark burned a year from her life, and Mara used it only when she had to.
Chapter 31Mara lit the mark three times on the stairs, without a thought.
Keeping it consistent
Keep the rules in your story bible and note the chapter where each rule first appears. AxiomStory builds a page for each rule of your world from your chapters and flags lines that disagree, like the example above.
Tools compared
| Tool | Best for | AI | Pricing |
|---|---|---|---|
| AxiomStory | Novels and series of any length: a story wiki, plot hole checks, and pictures and voices for your characters | Yes. Reads your chapters, checks continuity, and suggests edits you approve. Never writes your book unless you ask | Free to start, no card. Plans from $20 a month |
| Novelcrafter | A codex of notes plus AI with your own key | Bring your own key, from $8 a month | $4 to $20 a month |
| Scrivener | Offline drafting and research | No | One time purchase |
Questions and answers
Does my magic system need hard rules?
Not always. If magic rarely solves the plot's problems, it can stay mysterious. If heroes use it to win, readers need to understand its rules and costs.
How do I stop magic from breaking my plot?
Give it a real cost and clear limits, and check later chapters against the rules you set early.
Sources for this entry
- Brandon Sanderson: Sanderson's First Law: essay on magic systems (brandonsanderson.com)
- AxiomStory: official site
- Novelcrafter: official site (novelcrafter.com)
Practical guides and checklists are original editorial guidance. Official descriptions don't show how tools compare in use. Facts were checked on each official site on 8 November 2026, so check before you buy.
Keep reading
Worldbuilding
Worldbuilding Checklist
The worldbuilding questions that matter most for a novel, as a checklist that saves your progress.
Fantasy
Fantasy Writing Software
Software for fantasy novels: keeping a world, its places and its rules of magic consistent.
Continuity
Plot Hole Checker
How to find plot holes and continuity errors in a novel, by hand and with software.
Related sites
This is one of a set of references published by AxiomStory: Best Book Writing Software, Best Book Writing App, Best Novel Writing App. They share the same publisher and are not independent reviews.
Cite this entry
Best Fiction Writing Software. "How to Build a Magic System." Reviewed 8 November 2026. https://bestfictionwritingsoftware.com/magic-system/