Seas of Chaos is a high fantasy setting for Feng Shui. This aims to bring the action-movie flavor and simplicity of rules of Feng Shui to territory normally claimed by AD&D, Rolemaster, and Fantasy Hero. The difference between Chow Yun Fat mowing down hordes of mooks with a gun or Jet Li putting them away in hand-to-hand combat and Legolas dropping orcs left and right with his bow is or Gimli hewing them with his axe is just a matter of style.
The character creation process is designed to allow people to play pretty much any character or creature from a fantasy movie or novel, after renormalization for matching the power level of the rest of the characters. The rules for magic and Supernatural Creatures have been drastically expanded.
There are enough definitions I finally started a glossary.
The world is a large planet, about 32,000 miles in diameter, with a surface gravity of the usual 1 g and a reliable sun and moon; the rest of the sky includes a variety of lights, varying from stable fixed stars to slowly roiling nebulae to planets and comets that move around over years, days, or minutes. The world is covered in a Moorcockian-style opalescent primal Chaos, which devours almost all known materials, transforming them into other things or into more Chaos. A strong willpower will enable a person to survive a dunking in Chaos with only minor warping, but even great wizards are daunted by the prospect of transforming it into a single well-defined object.
The only materials that can resist the transformative power of Chaos are the True Elements: terra ultima, aqua ultima, nebula ultima, and the hypothetical ignis ultima. Terra ultima, also called Truestone, is a very dense substance that floats upon Chaos. Aqua ultima, also called Truesea, is an inert liquid (never freezing, never boiling) that always moves the outside of body of water, concentrating where Chaos is present. Nebula ultima, Truecloud, will shelter aerial travellers from Chaos storms and exhibits unusual magical qualities when its temperature is changed, making it a superb lift gas for dirigibles. Ignis ultima, Trueflame, is speculated to be the source of power of volcanoes, transforming Chaos into the other elements and building islands. No one reliable has ever gotten close enough to the stuff to sample it, however.
The action usually happens on the Great Islands. These islands float on top of the Chaos by virtue of their bases of Truestone; some are actually floating seas where Truesea insulates them from Chaos. On any particular island, the rules of magic and physics are well-defined. Between islands, magic is not reliable, and the safest means of travel is in a balloon or dirigible using nebula ultima for lift. (The second most reliable is something living that can fly— dragons soaring on the wind, boats made of wood that is insulated from gravity.) Seas may have a Truestone ocean floor with upthrust islands, or may have buoyant coral reefs or Truestone islands floating in them. (Truestone islands can sink to the bottom if forcibly submerged, but such events are very rare.)
At a player level, each island is owned by a different gamemaster; GMs may allow others to come play in their area, but a given GM is always the final arbiter of how physics works in their world, though they should be gracious about letting the current GM set difficulties for their own character. Deities are known to be able to reach different islands, but may approach different islands in different ways— the GM for an island is the arbiter of how they act, though GMs may wish to conspire over long-term plots bridging islands. The Children of the Dragon and Pyramid pantheons are already available for use.
For more inspiration, I have an in-character document on the physics of the world, a partly-historical, partly-fanciful overview of technologies that varying societies may use, and a compilation of medieval prices. Example islands are Élas, a collection of city-states inspired by the Greco-Roman milieu, Sheflek, an empire inspired by the Far East, Khoras, a high-magic setting whose seed crystal was a notion in Mary Gentle’s Rats and Gargoyles and uses many fine ideas from Earthdawn, and Rrallarra, the land of the cat people.
World-spanning legends abound. Here are a few...
The mythical place on the planet’s equator where there is an island that never moves.
A floating island where no deities have power. Its inhabitants are a wretched lot, denied the pinnacles and nadirs of human existence...
A realm where undead are the natural part of the ecosystem, and normal life is the stranger.