Genres
Hard fantasy
Fantasy that builds its world rigorously and logically, by analogy with hard science fiction, treating magic as a rule-bound natural force.
Hard fantasy is a term for fantasy whose worlds are built in a rigorous and logical manner, in explicit analogy with hard science fiction: Gary Westfahl's definition frames magic as "an almost scientific force of nature and subject to the same sort of rules and principles", and its plots parallel the scientific-problem story, with heroes who must solve magical problems logically. Randall Garrett's Lord Darcy stories, Lyndon Hardy's Master of the Five Magics and Brandon Sanderson's Mistborn are the named shelf.
The label maps onto the hard end of hard and soft magic: rules the reader knows, and endings the reader could have seen coming. Usage has varied and some critics call the term imprecise, but for serial writers it names a real promise: every stated rule of the magic is canon for hundreds of chapters.