HEAVENS AND OERTH
The world of GREYHAWK encompasses the Flanaess, the easternmost portion of the vast continent of Oerik, on the sphere of Oerth. Scholars from the Flanaess are certain that Oerik is the greatest of Oerth’s four continents, and that four great oceans surround these lands, as do four layers of the heavens and four depths of the underworld. Yet, even in this benighted age, almost nothing is known of the lands beyond the Flanaess, and little is understood of the regions above and below. Such knowledge is of small importance, claim the high and the mighty, for clearly the lands around Greyhawk form the center of all enlightenment and civilization. Some folks question this assumption, and they yearn to explore their world and its challenges.
Oerth is but one world among many, separated either by the gulfs of space, the invisible ether, or the fragile veils of reality. The craft and persistence of magic defines the nature of Oerth. Throughout recorded history, magical conflict and restoration have shaped this world. Some of these magic-driven events touch upon the history of other worlds, and portals sometimes open between Oerth and alien spheres. Few other worlds boast the magical profundity of Oerth, and many strange beings are found there, drawn by the lure of the supernatural. The majority of such entities make their homes far from the sunlit skies of Oerth’s surface, preferring to live secretly in lightless caverns below, where they may thrive and plot unseen.
If the paths of the underworld are hidden from view, the wise may still turn their attention to the heavens. All know that the sun travels once around Oerth every 364 days, the pale Great Moon, called Luna, waxes and wanes in fixed cycles of 28 days each, upon which the months are based. The aquamarine Lesser Moon, Celene, follows a path that reveals her full beauty but four times each year, thus showing the time for civilized festivals. Both Mistress and Handmaiden, as the greater and lesser moons of Oerth are also known, are held to be worlds in their own right, though few claim to have met any visitors from those lofty realms (or, for that matter, to have visited those alien worlds personally).