I might as well flesh this out a bit, even if I never use it:
- The First Age was a time of technological wonder. Over a thousand years ago, the spirits arose and magic came into the world. The First Age ended not in a Cataclysm, but in a century-long period of death and rebirth as the technological world struggled to survive and the spirits slowly awoke.
- Was the world of the First Age ours? More or less. I want to feel free to have PCs explore the ruins of Earth as we know it, but feel no compulsion to make everything recognizable or even coherent with respect to today’s geography. If I want to have the ruins of New York within walking distance of Mt. Rushmore… or a three-mile tall First Age skyscraper in the middle of a desert, I will.
- The world is animistic. Everything has a spirit attached to it. Most such spirits are unintelligent and unconscious (and for most purposes irrelevant), but they can be awakened. More important things have more powerful (and intelligent) spirits capable of leaving the spirit world. Even non-physical things (conceptions, ideas, emotions, movements) have spirits. These often set themselves up as gods. They seem to get something from worship or respect.
- There are two moons: one is deeply scarred – the legends say it was by ancient weapons of the First Age – the other, smaller moon hangs stationary in the Western sky.
- There are areas of strange magic that can mutate the spirits of things. This often results in the physical thing attached to the spirit being mutated as well. Normal animals have mutated into a near-infinite variety of strange monsters.
- People have spirits attached to them as well. Strangely, the spirit of a living thing is almost never separately sentient. Some people, however, have learned to control their spirit in a variety of ways – even to the point of being able to use magic themselves.
- Much of the world is carved up into petty domains ruled over by wizards. A few of these are benign rulers, but most are anything but… many wizards use forced labor in large-scale projects. Others use those they rule over as subjects in arcane experiments.
- A powerful empire in the West is ruled over by the Moon Lord. The Moon Lord forbids his subjects from worshiping the gods, and only those in the noble-houses of the Moon Lord’s empire may practice magic.