While the novel is often classed as science fantasy, it also belongs to the subgenre of planetary romance, which has affinities with fantasy[16] and sword and sorcery; it is distinguished by its inclusion of scientific (or pseudo-scientific) elements.[17] Planetary romances take place primarily on the surface of an alien world, and they often include sword-fighting and swashbuckling; monsters; supernatural elements such as telepathic abilities (as opposed to magic); and cultures that echo those of Earth in pre-industrial eras, especially with dynastic or theocratic social structures. Spacecraft may appear, but are usually not central to the story; this is a key difference from space opera, in which spacecraft are usually key to the narrative. While there are earlier examples of this genre, A Princess of Mars and its sequels are the best known, and they were a dominant influence on subsequent authors. Initially published in magazines with general readership, by the 1930s the planetary romance had become very popular in the emerging science fiction pulp magazines.[16]
The novel can also be classified as the closely related genre sword and planet, which consists of what are essentially sword and sorcery stories that take place on another planet. A Princess of Mars is widely considered to be the archetypal novel of the sword and planet genre.
The novel also shares a number of elements of Westerns, such as desert settings, women taken captive, and a climactic life-or-death confrontation with the antagonist.[18]
