Three widely cited principles by Brandon Sanderson that help writers design magic systems that serve their stories instead of breaking them.
Sanderson's Laws of Magic are a set of three guidelines that fantasy author Brandon Sanderson developed to help writers think about how magic interacts with plot. They're not actual laws you must follow; they're more like design heuristics. The first law is the most famous and deals with when magic can solve problems. The second addresses limitations and costs. The third reminds you to expand what you have before inventing something new. Together, they offer a practical framework for building magic that enhances your story rather than undermining it.
These laws give you a vocabulary for diagnosing problems in your magic system. If your climax feels unearned, the first law tells you why. If your world feels bloated with ten different power sets, the third law tells you to simplify. You don't have to agree with every point, but understanding these principles will sharpen your instincts.
Sanderson built these laws from his own practice. Mistborn's Allomancy is the clearest demonstration of all three principles working in concert.
Sanderson uses Tolkien as his primary example of the First Law in action: Gandalf's magic is soft, so Tolkien wisely avoids using it to solve major plot problems.
They're guidelines for thinking about magic design, not commandments. Plenty of great fantasy breaks them. Use them as diagnostic tools, not dogma.
The First Law says magic that solves problems must be understood. Soft magic is fine; it just works better for creating problems and atmosphere.
Always ask: what does this cost? What can't it do? What goes wrong when it fails? Those answers are where your best scenes live.
Take a magic system you've designed (or borrow one from a favorite book). Test it against all three laws. Write a paragraph for each: Does the reader understand the magic well enough for it to solve your climax? What are its most interesting limitations? Could you deepen existing elements instead of adding new ones? Revise one aspect based on what you find.