Machineries of Empire is a series of military science fiction/science fantasy/space opera novels by American writer Yoon Ha Lee and published by Solaris Books.

The main trilogy follows the young infantry captain Kel Cheris and the traitorous general Shuos Jedao in a war among factions of a despotic interstellar empire, the Hexarchate, whose esoteric technology is based on the population's adherence to the imperial calendar.

The power of the hexarchate is linked to a calendar system, where citizens' adherence enables the use of exotic technologies that defy traditional physics.

Approximately 400 years before the events of the novel, General Shuos Jedao suppressed a heretical rebellion, but in doing so, caused the deaths of over one million people.

Jedao sets out to prevent an invasion by the Hafn, a foreign enemy threatening the hexarchate, but his true motives remain unclear.

Jedao, without full knowledge of his past actions, is placed in command of a fleet with orders to subdue rebel factions and restore the status quo.

The amnesiac Jedao struggles with his lack of knowledge about his past actions and his role as a tool for Nirai Kujen, while Cheris is still determined to dismantle the hexarchate.

Cheris, now firmly in control of the situation, decides to rebuild a new system to replace the hexarchate, one that doesn't rely on the oppressive calendrical technology.

The review concludes with a positive recommendation for the novel, stating that "readers willing to invest in a steep learning curve will be rewarded with a tight-woven, complicated but not convoluted, breathtakingly original space opera.

"[6] Aidan Moher of Reactor praised the way in which Lee takes the tropes of military science fiction and uses the concept of the calendar "that is beyond our understanding of physics—rendering it, essentially, magical."

The same reviewer wrote that "Ninefox Gambit might not work for everyone, but for those itching for dense worldbuilding, a riproaring plot, complex relationships, and military SF with a deep imagination, it’ll do just the trick...