The Earth got used up, so humans moved out and terraformed a whole new galaxy of Earths. Some rich and flush with the new technologies, some not so much.
The Central Planets, them’s formed the Alliance, waged war to bring everyone under their rule; a few disagreed on that point. There was a war over it.
After the War for Unification, many Independents (also called Browncoats)—those who fought against the Alliance and lost—drifted to the edge of the system, far from the Alliance control.
Out on the Rim, people struggle to get by with the most basic of technologies. Out on the Rim, a ship will get you work. A gun will help you keep it.
A captain’s goal is simple: Find a crew. Find a job. Keep flyin’.
Serenity RPG is a different type of futuristic setting. Not everyone is running around with a laser blaster, nor do we transport people through space by scrambling their molecules.
In the ‘Verse of Serenity, a spaceship captain might ride a horse when he’s on land and tote a six gun or a Bowie knife. The blending of the future and past is what makes it a unique place to be.
A crew in the game is like family—you get to know each other and depend on one another.