It is based on Christopher Moeller's two critically acclaimed Iron Empires graphic novels, Faith Conquers and Sheva's War.

The game fiction assumes a race of sentient wormlike creatures called Vaylen which infect humans and take over their brains.

This infection happens on a massive scale, eventually taking over whole planets in the process.

The phases of a Burning Empires campaign are infiltration, usurpation, and invasion, and these correspond to the stage of the Vaylen infection on the planet.

Typically, the GM or Game Master will take on the role of the Vaylen invaders, while the players will take the role of mostly humans, who are trying to actively stop this invasion.