So, in order to participate, I'll post up a my starting write up from the last world I started building, Troika. Based on the trinity of the dragon gods Io (creation), Tiamat (evil), and Bahamut (good). The creation myth I pulled straight from Io's Wikipedia entry. This is all I ever got going for Troika before I abandoned the idea.
The Two Voids
In the First Void, Io existed alone. There was nothing else, and until Io willed it there could be nothing else. Io voluntarily shed some of his blood in the Shadow Void, which created the potential for other things to come into being. Only then could there be other gods and other creations. Most races know only of the Shadow Void, which is why they have no myths of Io.
Tiamat and Bahamut
According to myth, Io's first child was a small, simple-minded dragon called Vorel. Vorel's name means "beautiful" in Draconic, for beautiful it was, perfect of scale and form. Next Io created a pair of children, male and female he created them: Bahamut and Tiamat were their names. Io intended them to grow up and mate, producing children that combined the best traits of each. Instead, the two were immediate rivals, yet Io would not choose a favorite between them. After many failed schemes to make herself look better and Bahamut worse, Tiamat hatched a diabolical plan: she slew her sibling Vorel and framed Bahamut for the awful deed. Io, however, carefully sought out the truth, and sorrowfully banished his daughter Tiamat from his presence. Tiamat turned utterly to hatred and Evil, while her brother Bahamut, ever her rival, turned to Good in order to oppose her. So it was that Io lost three of his children: the first to death, the second to Evil, and the last to Good.
First Age - Jotunstiden, Age of the Giants
Moradin and the dwarves began their life on Troika underground. There they carved out their Great Halls, and deep mines while perfecting the arts of smithing. They dug ever higher, until they broke the surface and discovered a world populated by the offspring of Annam. The giantish races quickly captured and enslaved what dwarves came to the surface. The giants even smashed and broke open the surface to root out more dwarves, but even their smaller brethern, the ogres and trolls, could not penetrate the deeper tunnels. Still, many dwarves were captured and enslaved.
Troika and the Giants
Tiamat turned her attentions to Troika. Troika was a world of giants, ogres, trolls, and their dwarven slaves. When Tiamat first came to Troika, Annam, Father of the Giants was the supreme god. After an extended power struggle, Tiamat slew Annam in single combat. Since then the Jotunbrud has been led by Tiamat.
Second Age - Age of the Dragons
Tiamat seeded Troika with her offspring, the chromatic dragons. Lizard folk, yuan-ti and kobolds were set loose, and they pushed deeper into the dwarven holds, enslaving even more dwarves to give to the giants.
Corellon Larethian and Bahamut came to Troika, bringing elves and metallic dragons. This angered Tiamat, and started The Dragonwars, which raged for centuries. The elves were able to aid the dwarves in overthrowing the giants, gaining their freedom. Eventually, the chromatic dragons were defeated, and driven to deep lairs. Much devastation was caused in The Dragonwars, and the elves looked to heal the land.
Third Age - Sylvan Age
The elves developed the Talent of Woodsinging, a combination of magic and song that aided plants in growth, and allowed the harvest of wood without cutting down a tree. With the aid of magic and the dwarves, they erected monolithic statues, temples and cities. The arts experienced a renaissance from both dwarven craftsmen and elven artists. High magic is pushed to it’s limits as available spells reaches new levels.
The elves become reclusive and dedicate themselves to art, music and magic as opposed to rule. The Dwarven Houses spread commerce and with money comes power. They build many more major cities and fortifications, most near mining sites and major trade routes. Continued mining going deeper and deeper reveal a deeper, hidden world releasing orcs and other goblinoids onto the surface.
Orcish Age. Unable to stem the tide of the fast reproducing humanoids the Dwarven Empires fall. Trade collapses and the elves become even more reclusive. The humanoids use a “slash and burn” technique across the lands, leaving many areas devastated. This upsets the land itself, which causes the “Great Upheaval”. Volcanos, earthquakes and tsunamis change the surface dramatically. It is an age of darkness, with many humanoid kingdoms using the other races as slaves.
Age of Man
Able to most easily adapt, humans spread throughout the world. New cities are build on the bones of the old ones, and the old dwarven trade routes are being used again. Most of the world is being “rediscovered”.
Elves. Many different types, but they fit mostly in the same mold. High elves being most like the old ruling elves (Tolkien elves), while others became more “native”, living closer to the natural world. Similar to Native Americans, aborigines, ect. Drow not an evil offshoot, but an underground race that sought to take the battle to the humanoids in their own world. All three groups see the others with distrust.
Dwarves: In the Upheaval, many clans were cut off from their holdings, resulting in two distinct groups, surface and underground. Underground dwarves became more insular, and fit the mold as traditional dwarves. Surface dwarves have lost the natural abilities with mining and being underground, but have excelled in metalwork and trade. Some surface clans and underground clans work closely together, the surface dwarves trading goods and raw materials to spread around the world.
Halflings: The once peaceful and serene halflings have taken on an edge since the Upheaval. They have discovered a natural affinity for life on boats, but strangely do not like deep water, sticking to rivers, smaller lakes or coastal waters. Image like gypsies or tinkers, with “villages” of rafts, barges and skiffs traveling around. Distrusted as thieves, and bandits. Stories say they do not reproduce, but steal human children to replenish their numbers.
Gnomes: Brilliant but wild inventors! Gnomes mix magic and technology in interesting, but unpredictable ways. Often rediscovering lost technologies and magics. Think steam punk. Wild magic.