Science Fiction and Fantasy are notoriously difficult to define, and possibly even more difficult to distinguish. One might claim that Science Fiction provides a scientific explanation for all phenomena, whereas Fantasy mostly takes the supernatural for granted. However, the science behind these explanations is often no more than mumbo-jumbo, especially in the pulp magazines. Hence, it might be said that the difference is more one of stage props: on the one hand we have spacecraft and phasers, on the other hand magic carpets and wands of smiting.

Now, since Arthur C. Clarke claims that "any sufficiently advanced technology is indistinguishable from magic", this distinction also becomes blurred, and the area in which it is most blurred is Science Fantasy. Here, we find the props that are typical for Fantasy explained in a manner typical for Science Fiction: monsters become aliens, and magic artefacts become relics of forgotten science.

The Martian stories of Leigh Brackett might be regarded as Science Fantasy, as well as M. John Harrison's Viriconium novels, or Gene Wolfe's Book of the New Sun. Many works by Edgar Rice Burroughs, especially his Barsoom novels, clearly fall into this category.