Hidden in the dark depths of the outer fringes of the Elemental Chaos, the malignant and maddening Outer Gods lie in waiting, gazing upon the Planescape with intentful eyes. Now, their numberless hordes invade it, desiring only to warp and reform the multiverse to their self-justified, chaotic and disturbing worldview. The Outer War has begun.
However, the invasion hasn't quite gone to plan, and now they find themselves stalled by a new generation of gods taking the place of those they so passionately obliterated.
As a result of the Outer War most of the gods and races of the Planescape are now dead. In their place is a new generation, either emerging from the broken essence of dead gods or seizing the chance to fill a power vacuum. They usually espouse the same alignment as their forebears, but their portfolio and domains can differ depending on their relationship to the deceased deity. Currently, beings of both the Inner and Outer Planes are fighting a ruinous war against the Outer Gods, and either the Outer Gods will be crushed and (relative) peace will return or the Planescape will be completely ravaged. So far certain planes and godly realms, including the Material Planes, have been fortunate enough to be untouched by the war.
The actual setting of Warmonger is a layer of the Prime Material Plane, the planet Jurf. Jurf is an incomplete divine project, built and populated by an unidentified god just prior to the outbreak of the Outer War. As a result, much of the planet is covered in shadowy void, and only six continents are stable: Sundermay, Sylnemer, Lochamand, Parmedoor, Gufelban and Igentar. The prestigious title of Creator is the subject of constant and inaccessant bickering among the many gods worshipped here.
Key to the diversity aspect is regional hierarchy. On average: each of the 6 Continents is divided into 20 Regions, each region is divided into 8 Subregions, and each Subregion is divided into 4 Provinces. Every Subregion is given a Cold, Temperate or Hot climate, and each Province is given a specific terrain type (Desert, Forest, Plain, Underground etc.), weather system and list of typical NPC encounters. Works out at around 3,840 Provinces!
Dwarf fans will be pleased to know that in fact it was the Dwarves who once ruled the world, not the pretentious High Elves.
Oh and there's guns and airships.
Sammatar is a region on the northern coast of Igentar. Being invaded by numerous cultures over the centuries, society is a rich and cosmopolitan melting pot. It has been prosperous and peaceful since the Igentar Accords.