Magic system
A magic system is the set of rules for how magic works in a story: where it comes from, what it can’t do, and what it costs.
People usually split them into hard and soft. In a hard magic system, you understand the rules well enough to guess what’s possible and what isn’t. In a soft one, magic stays mysterious and is there for atmosphere and wonder, not for solving problems. Most books land somewhere in between, often with clear rules for the main character and fuzzier magic elsewhere.
Brandon Sanderson has a well-known rule for this: an author’s ability to solve problems with magic depends on how well the reader understands it. The logic is simple. If you don’t know the rules, a magical solution feels like it came out of nowhere, however consistent the author thinks it is.
Limits and costs matter more than powers. If magic drains the person using it, needs a rare ingredient or takes something away from them, every spell has a price you can feel. If magic has no limits, the stakes fall apart, because there’s no reason the problem can’t just be magicked away.
Magic system: common questions
What is the difference between hard and soft magic?
Hard magic has clear rules you can follow and even predict. Soft magic stays mysterious and is used for wonder and atmosphere rather than solving problems.
Why do magic systems need limits?
Without limits there are no stakes. If magic can fix anything, you have no reason to worry about the characters.