Middangeard: Schemes of the Kraken Cult
I've done my best to hold true to the cliches and and stereotypes of D&D while expanding them, with a few (hopefully) tasteful reinterpretations. The following are some of the main themes our world revolves around:
There is magic everywhere. 20th level characters and beyond abound, countless great powers influence mortal affairs, and the gods take active roles in advancing their agendas. Artificery, advanced alchemy, and firearms in the past century have ushered in a new era. Epic magic of ages nigh-forgotten and shrouded in legend still work forces out of sight. Lost giant technology, Elven magic developed past 9th level spells, and the world-rending forces of dragons are just a few examples.
The Planes and their Influence
Our world uses the Great Wheel cosmology, but both the Outer and Inner Planes are much closer to the Material. Portals, coterminous regions, and outsiders are as common as halfings in many places. Sigil, the great city at the center of all worlds, is a little different too: here it is a vast metropolis divided in wards by interdimensional factions and guilds.
Giants, Dragons, their Wars & Legacies
The gods saw to the shaping of the planes, and begat the Titans, demigod beings of awesome power who first walked the multiverse. From them in turn came the Giants, who developed Arcane magic to bend the fabric of reality to their will. Around this same time though, the first Dragons of old arose from the earth itself, masters of innate Sorcery. Inevitably the two races clashed. Their wars were fierce and terrible, rending mountains and ruining the empires of both. The myriad descendent races of both sides still harbor their inherited hatred for the other.
Wizardry vs. Sorcery
The civilized lands of humans, dwarves, and other familiar races continue the Arcane tradition of scholarly wizardry learned from their forebears. They see the appearance of sorcery in a bloodline as a taint, proof of intermingling with evil cold-blooded creatures. The dragonkin for their part see sorcery as the natural order, proof of a connection with the underlying fabric of reality, and view wizardry at best as a poor substitute and at worst as a meddling with the natural order. In the strictest human lands, witches, warlocks, and others gifted with their magic through bargains are sorted in with sorcerers and hunted down. In dragonkin lands, learned magicians are sacrificed to ancient wyrm overlords.
Runic symbols channel powerful magic. Rune Scribes spend lifetimes unlocking the mysteries of symbols passed down in secrecy through generations, adventurers discover lost symbols of power in ancient giantese vaults, and still others are born with Master Runes emblazoned on their flesh- like Dragonmarks of other worlds- or develop them after powerful magical influences. Other Lesser Runes are common in many classes' arcane writings, but Master Runes may make or break kingdoms and destinies.
Commune with the spirit world is already present in many traditions, but here it has a strongly felt mechanical aspect. Shamans, Totemists, Witches, and Animancers all wield the power of spirits directly, along with many other new paths of existing classes. Black markets and cruel powers trade in souls trapped in gems to fuel malevolent ends.