Hub World
Just your average run-of-the-mill fantasy world ripe for the attention of a band of chaotic murder-hobos.
The main feature of the planet are the two colossal clockwork caps, The Hubs, hover in low-orbit over each of the poles. Hundreds of kilometers wide, these titanic and ancient devices amplify the weak rays of the sun and focus the fields of magic native to the planet. Though all knowledge of the original builders has long faded through myth and into obscurity, the abundance of richly furnished ruins about the planet bearing the same clockwork mechanics tells of a race powerful enough to travel the stars.
Just shy of 200 years ago the exploration of one of these ruins unearthed a literal Pandora's box of disasters and strife. Gunpowder. Though only a handful of the ancient's firearms were recovered, the knowledge of magical gunpowder slowly crept through the alchemist community. With quantities limited and dwindling, it became Hub World's collective obsession to reproduce gunpowder. The only thing slowing the advancement of firearms was the fact that this task was impossible for all but the most skilled, lucky, or those belonging to guilds old and powerful enough to lay hands on an original sample.
The few dozen firearms also recovered from the delve have since thrown Hub World into chaos. Entire nations throwing themselves into total war just to ensure none of their neighbors have a single original piece. Perhaps worse were nations that eradicated any unsanctioned alchemists in those brutal conflicts. However nothing can stop invention and engineering. Crude replicas of the ancient firearms have, while still exceedingly rare, already started circulating the wealthier nations. War is everywhere and a new age is upon us, the age of the mercenary.