From the Introduction:
Twilight Age is a fantasy RPG set on the world of Atreion, where a magical cataclysm almost destroyed the sun, a decadent race schemes to restore their lost empire, and mad gods wage a campaign to escape an ancient prison and exterminate mankind. Here is a world where you can -
Play the game of war and intrigue for the highest stakes, a kingdom of your own;
Explore a strange, sometimes eldritchly beautiful, always dangerous world forever changed by the Wounded Sun;
Stalk the wastelands as a hunter of demons;
Seek out the ruins of lost cities and try to bring back their buried treasures;
Join a desperate band of outlaws fighting for freedom against the tyranny of a slaver empire;
and much, much more.
This worldbook is divided into three parts; the Getting Started and Known Worlds sections are for both player and game master alike, while the GM's section provides extra material for the game master.