The Imperial Radch trilogy takes place in and around the Radch, a massive human empire stretching across galaxies in the far future. In the Radch, gender is not a culturally understood concept, and all people use one pronoun: she/her. Ann Leckie’s works draw on many existing science fiction traditions, especially with regard to gender. The single pronoun culture of the Radch harkens back to Ursula K. Le Guin’s groundbreaking novel, The Left Hand of Darkness, which takes place in a world where everyone uses he/him and everyone’s sex is in flux.

The Radch is ruled by Anaander Mianaai, a despotic emperor with thousands of cloned bodies that all share the same consciousness. There are human cultures outside of the Radch, but all of them are under constant threat of violent annexation. Humans are also in contact with three alien species: the amphibious Geck; the furry, many-legged Rrrrrr; and the violent and incomprehensible Presger. The Radch communicates with the Presger through Presger Translators. Presger Translators look human but are not; their behavior is often unsettling because the Presger made them. The only reason the Presger do not destroy humans is because of a diplomatic treaty.

The Radchaai people have developed artificially intelligent spaceships and space stations.