The planet Roost is a terrestrial planet with a single, large continent surrounded by a vast ocean. Due to the lack of any nearby celestial bodies, the oceanic tides are nearly non-existent and are mostly calm. There were once small regions with pockets of forests, but the majority of its landmass consisted of lush savannas that allowed animals to follow an evolutionary path favoring herbivores that graze in herds and over 40,000 species of avians, prompting early pioneers to name the planet Roost.

Beyond a few small colonies of settlers, Roost has remained mostly untouched by civilization since its discovery and throughout the span of many galactic governments, it has been considered a backwater world of little importance. After the fall of the New Republic in Year 21, a collection of organizations that shared anti-imperial sentiment called the Unity Protocol renounced the Emperor's authority and developed a bastion of rebellion in the outer rim, inviting all who would hear their call. The call to freedom beckoned an unfathomable amount of refugees from the war-torn territories of the fallen New Republic. Those refugees came with their ships, their supplies, and their dreams which sparked a massive world-wide settlement effort on Roost which rapidly converted the planet into an ecumenopolis.

Lacking sufficient agricultural capacity to support its population, Roost relies on interstellar trade to import food. What the planet lacks in agriculture, it makes up for in industrial capacity. Its sprawling cityscape contains sectors that are dedicated megafactories which contribute to the galactic economy by producing chemicals, pharmaceuticals, starships, and military items.