Medieval Player's Manual

From the back cover: 

"The Medieval Player's Manual gives you everything you need to have exciting adventures in the age of Christianity and crusade. This is not Hollywood medievalism, but the real thing. The Medieval Player's Manual has been exhaustively researched to provide rules that reflect the actual beliefs of the period. Ars Magica line developer David Chart has written a book that is both authentic and playable. Take your d20 game back to the Middle Ages with the Medieval Player's Manual. The book includes:

• Three new magic core classes (cunning man, natural magician, and theurge) and two support prestige classes (necromancer and theophanist).
• New systems for medieval magic like folk charms, alchemy, astrology, astral charms, and theurgy.
• Three new religious core classes (priest, canonist, and saint) and five supporting prestige classes (crusader, templar, prelate, hermit, and mystic).
• The introduction of Charisms, new feats representing gifts of miraculous power granted by God.
• Rules for holding academic disputations, creating theories, and writing books.
• Non-combat core classes like scholar and artist.
• Overviews of the Christian Church, the political history of the time, philosophy and the arts, and medieval laws and beliefs.
• Suggestions for alternate campaigns, like the Abbey Campaign and the Court Campaign, and intriguing historical "What ifs?".
• Backgrounds and stats for important people of the day, like Empress Matilda, Archbishop Anselm of Canterbury, and natural magician Adelard of Bath.

The book also presents "Kin of the Conqueror", a campaign setting detailing the anarchic period after the death of King William the Conqueror. From 1087 to 1154 the British Isles and northern France were convulsed by wars over his legacy. Plunge into adventure with Kin of the Conqueror, or use the rules to explore other parts of the medieval world. Either way, the Medieval Player's Manual is your starting point for a new d20 experience."