The second edition of Ars Magica was published in 1989. The rule book is 156 pages long, with a front cover featuring a color illustration of a magi peering into a crystal ball.
The game is set in a mythical medieval Europe and is primarily focused on magic. Players control one of three character types: magi, companions, or grogs. Magi, also known as wizards, are the most powerful. Grogs are essentially common soldiers, while companions consist of scholars, healers, thieves, and military leaders. Character abilities in the game fall into three categories: talents, skills, and knowledge.
Magi are able to learn five "techniques" (create, perceive, transform, destroy, control) and ten "forms" (animal, water, air, body, plant, fire, image, mind, earth, power). Magical combinations are then determined by cross referencing the various techniques and forms. Magical terms in the game use medieval Latin.
Much of the book is dedicated to the game's highly detailed magic system. Also included are weapon, armor, and ability charts, information on laboratories for non-adventuring magi, a complete bestiary with monster and animal statistics, four pages of character sheets, and a variety of other background materials.