"As the uncaring gods warred in Heaven, the Moon was cracked and flung to the Earth. A great upheaval followed as the shards of the moon struck the cities of dwarves, rent the nations of elves and drowned the kingdoms of men. All that had been built was shattered. All that had been gathered was scattered.
Today, the world knows nothing of the Fallen Moon, the skies are empty save for distant stars. The oceans are shallow and the tides sweep the land. Yet dwarves, elves, men and tieflings prevail. But some, those born with seething sorcerous blood, look up to the sky, at the poisonous pale green moon glaring down on them. Ever full, never half, an accusing eye directed at their sins of wizardry and chaos."
- From the Book of the Pale Moon, written in the 2nd century of the Era of the Leaden Dawn by the magic-user Aglemore the Lunatic
Note: The Book of the Pale Moon is a grimoire containing the magic-user spells: summoning, force of forbidment, howl of the moon, strange waters II, seven gates, contact outer sphere, weird vortex and witchlamp aura.
Once per day, the owner of the book may cast any one of the spells contained in the book as a magic-user of his level. After casting the spell, he must make a saving throw vs magic at a penalty. The penalty is the difference between his current level and the minimum level required to cast the spell (if he is of higher level, this can become a bonus). If he fails the save, he will dream poisonous dreams of a pale moon. He will thrash and howl in his sleep and cannot be woken until dawn. Such a sleep is not restful at all. A magic-user or tiefling will not be able to prepare spells, and all his rolls on that day will be at a -2 penalty.
The spells in the grimoire can be studied and copied normally. This will not having any ill effect.