Project: Redcap; the crossroads of the Order


Magic theory

From Project: Redcap

Magic Theory, sometimes called Hermetic theory, refers to the set of universal magical principles developed by Bonisagus and the other Founders.[1] Magic theory is a body of knowledge that describes how magic works, and transcends the scope of any single Art.

There is an Arcane Ability called Magic Theory that represents knowledge of, and practical experience with, magic theory.[2]

Importance of Magic Theory[edit]

Magic theory is Bonisagus's second great invention, after Parma Magica.[1] It is a single, universal theory that assimilates the magical concepts and practices from many traditions.

According to the the ArM5 rule book,

The most immediate advantage of Hermetic magic was that it allowed wizards of diverse magical backgrounds to share their knowledge. Before Bonisagus’ theory, the practice of magic had been highly individualized and therefore limited in scope. With the ability to share and accumulate knowledge, Hermetic magi gained an immense advantage over other wizards.[3]

Thus, magic theory makes it possible for magi of the Order of Hermes, even those of different Houses, to teach magic to one another and to write books about the Arts. Magic theory also makes it possible for any magus to create a longevity ritual, bind a familiar, enchant a talisman, or create other enchanted devices.

Characteristics of Magic Theory[edit]

While Bonisagus's theory is very useful for making magic understandable, that is not the same as making it entirely systematic or predictable. The ArM5 rule book points out that every magus's magic is a little bit idiosyncratic[4] and using magic is complex and not entirely predictable.[5]

The Ars Magica rules don't describe the actual tenets of magic theory in much detail. Magi know a lot about magic theory, but players only need to know how the magic rules work. Magic theory incorporates various forms of occult knowledge including astrology[5][6], alchemy[7], and the magical properties of gemstones[8].

The Laws of Magic are part of magic theory and the rules occasionally refer to them.

Arcane connections are important in magic theory, allowing a magus to affect a distant person, creature, or object through sympathetic magic.

Limitations of Magic Theory[edit]

The Limits of Magic describe what magic can't do.

While Hermetic theory is highly useful and successful at explaining many kinds of magic, it is not fully comprehensive. There have always been forms of magic that Hermetic theory can't explain. Even some well-known spells of the Order of Hermes, such as Wizard's Communion[9], Aegis of the Hearth[10], and Whispering Winds[11], can't be fully explained in terms of conventional magic theory. There are also mysteries, which teach secret magical knowledge that has never been incorporated into magic theory.[12]

History of Magic Theory[edit]

Bonisagus the Founder developed Hermetic Magic Theory, which assimilates and extends the knowledge of earlier magical traditions such as the Cults of Mercury, Mithras, and Osiris[13]. Bonisagus created it by carefully studying spells from several different magical traditions and identifying the commonalities among them. By extracting and formalizing these common principles, Bonisagus created a framework that made it easier to learn, teach, and record magical spells and enchantments.[14]

Bonisagus started and led this work, but he had help from many of the pre-eminent wizards of his time. Trianoma located powerful wizards and convinced them to learn Parma Magica and then come share their own magical knowledge with Bonisagus, who then incorporated their teachings into magic theory.[15] In turn, they studied Bonisagus's new theory and expanded their own powers. These magicians became known as the Founders.


  1. 1.0 1.1 Ars Magica Fifth Edition, p. 9, "The Foundation of the Order"
  2. Ars Magica Fifth Edition, p. 66, "Magic Theory"
  3. Ars Magica Fifth Edition, p. 75, first paragraph
  4. Ars Magica Fifth Edition, p. 30, second paragraph
  5. 5.0 5.1 Ars Magica Fifth Edition, p. 75, third paragraph
  6. Ars Magica Fifth Edition, p. 84, "Sympathetic Connections" (inset)
  7. Ars Magica Fifth Edition, p. 101, "Longevity Rituals"
  8. Ars Magica Fifth Edition, p. 110, "Shape and Material Bonuses" (table)
  9. Ars Magica Fifth Edition, p. 160, Wizard's Communion
  10. Ars Magica Fifth Edition, p. 161, Aegis of the Hearth
  11. Ars Magica Fifth Edition, p. 127, Whispering Winds
  12. The Mysteries Revised Edition, p. 4, "What are the Mysteries?"
  13. Houses of Hermes: True Lineages, p. 5
  14. Ars Magica Fourth Edition, p. 64, "Hermetic Magic"
  15. Ars Magica Fifth Edition, p. 9, "The Foundation of the Order"

Legacy Page[edit]

The history of this page before August 6, 2010 is archived at Legacy:magic_theory