Rationalist fiction

Rationalist fiction (or rational fiction) is a subgenre of speculative fiction that emphasizes consistent world-building and the application of rationality to resolve narrative conflicts. Major news outlets, including The New York Times and The Washington Post, have identified works in the genre as sharing a core focus on human cognitive processes and logical problem-solving. The genre often functions as a "pedagogical fiction," where the narrative intentionally teaches the reader specific mental models or scientific concepts through the characters' actions.

The movement's development is often linked to the 2010 work Harry Potter and the Methods of Rationality (HPMOR) by Eliezer Yudkowsky, which utilized J. K. Rowling's universe to explore cognitive science. While the genre's formalization is associated with the LessWrong community, it draws influence from the Golden Age of Science Fiction and the rigorous world-building traditions of authors like Isaac Asimov. Unlike traditional hard science fiction, which focuses on the accuracy of the physical sciences, rationalist fiction focuses on the accuracy of the cognitive and social sciences.