The back-story (short summary) is that all civilizations, ranging from powerful kingdoms to enslaved races were all driven into hiding due to an overwhelming darkness (creatures) which came from another dimension to feed on the world and its inhabitants. Most of the population didn't survive, despite their protective magic or stone fortresses. A thousand years later, the darkness simply vanished, and the world became quiet. No one knows exactly when the dark creatures disappeared, but civilizations began emerging from their underground cities and mountainous castles.
The setting is high fantasy, and although there are minor factions emerging across the world, there are four primary realms of power (the player chooses one). Minor factions are not important currently (no design yet) but are composed of the same races as those which make up the primary realms. (40+ total).
The civilizations were not just slaughtered, but the world itself was consumed. These horrors devoured plant-life and some of the largest even devoured mountains. Entire seas were drank empty or polluted by these beasts. Upon emergence from their safe homes, generations of even the oldest races know little but stories of the "old world". Most inhabitants are still too afraid to emerge from what they know as home, so only the brave few have explored outwards to this new world, and in doing so invoke magic to regrow forests, old tricks and knowledge to heal the soil, and old fashion hard work to bring their environment to life again.
The Realm of Man, composed of Humans, Dwarves, Centaur, Giants, and other hardy creatures. Once rulers of all the world, they now are humbled to equality with the rest of the world's power. Their geography contains more mountains than elsewhere, and most did not live underground but in fortresses high in the mountains. Grassy fields, open plains, and a sea or ocean coast for the Merfolk (as well as some geography for the frogloks) contain their area.
The Realm of Ancients, composed of Elves, Pixies, Treants, and other forest creatures. These civilizations are among the oldest in the world, empowered with the highest forms of magic. To protect themselves from the darkness, they used powerful Ward magic. Their geography consists of deep forests, glorious waterfalls, and magical lakes.
The Realm of Dragons, composed of Goblins, Orcs, Trolls, Lizardmen, and other enslaved races, once ruled by the dragons. During the reign of Man and the Ancients, the dragons were hunted to near extinction for their wealth, slain for the fame, and enslaved for their power. Without the dragon's leadership, these barbaric civilizations were quickly overthrown by the other Realms and have so been enslaved since history was first written. Without the proper environment, a dragon egg is like a fossilized rock, and these treasures have been kept buried for thousands of years. The Realm of Dragons were the first to prophesy the end of days, and rebelled against their slave masters, burrowing themselves deep underground, towards the center of the earth. While most were dug out by the darkness, those which survived have resurfaced free of oppression and slavery ready to begin anew, with the Dragon eggs now ready to hatch. Their geography is friendly towards heated environments such as deserts, lava-like areas, and caves/caverns (often full of crystals, or a part of a volcano).
The Realm of Unrest, were civilizations which survived the darkness, but were heavily tainted by it. Skeletons, Zombies, Vampires, and other tormented creatures. Unlike the Men's lofty fortresses, the Dragon's deep caves, or the Ancient's Wards, these civilizations somehow survived within the world, but not without being driven into madness. Many were mercilessly slaughtered by the darkness, only to be resurrected by them to suffer an eternity undead. Others were civilizations which feared the horrors enough to commit mass suicide with the hope of their necromancer's power to resurrect them when the darkness had ended. Their geography consists of something similar to a mix of the desolation and restoration. Their warped minds restore the land to become something reflecting their own nature; vile, twisted, and dead. Yet within this death are bits and pieces of what could be considered life.