Parma Magica

Parma Magica is a Latin phrase meaning "Magical Shield." Parma Magica is a spell-like ritual that provides Hermetic Magi with Magic Resistance. It provides a general-purpose Magic Resistance that combines with the Magic Resistance granted by the magus's Form score.

Parma Magica was invented by Bonisagus. It is one of the two great discoveries attributed to him; the other is Hermetic Magic itself.

The exact details of Parma Magica have varied a little through the lifetime of Ars Magica.

Parma Magica in Fifth Edition

Parma Magica is the only form of all-around Magic Resistance in Fifth Edition Canon. Non-Hermetic wizards (and diabolists) lack anything that provides Magic Resistance against all Forms.

In addition to providing Magic Resistance, Parma Magica also blocks the adverse social effects of the Gift. This enables magi to have normal social interactions with one another, form friendships, and found long-lasting covenants. In Fifth Edition canon, Parma Magica made the Order of Hermes possible (ArM5, page 9).

In ArM5, Parma Magica is a an Arcane Ability that can only be learned by characters who have The Gift. The secret of Parma Magica is only taught to members of the Order of Hermes; teaching it to outsiders is a serious crime (ArM5, page 66). Hermetic apprentices are n are not taught the full secret of Parma Magica until after they have passed their Wizards Gauntlet and sworn the Hermetic Oath.

Houses of Hermes True Lineages includes some variations on Parma Magica that could be invented as a Hermetic Breakthrough.

Fifth Edition References

Invention and social effects of Parma Magica, ArM5 page 9.
Ability Description, ArM5 page 66.
Activating and De-Activating Parma Magica, ArM5 85
Formula for Magic Resistance granted by Parma, ArM5 85
Sharing Parma Magica, ArM5 66, 85

Parma Magica in Fourth Edition

Mechanically, Parma Magica worked the same in Fourth Edition as it does in Fifth Edition. There is no mention of it having any effect on the social impairment of The Gift.

Parma Magica in Second and Third Edition

Parma Magica in Second and Third Edition provided Magic Resistance. In addition, the text noted that Parma Magica also blocked the "everyday" magic of a beautiful sunrise or a well-prepared meal. This set magi apart from other characters and made them think and act even more differently from mundanes.

In the Third Edition sourcebook, Houses of Hermes, it was noted that some members of House Jerbiton avoid using Parma Magica so they can fully experience beauty.

Parma Magica in First Edition

Parma Magica in ArM1 was not an Ability at all, but a Rego Vim General spell. Furthermore, Parma Magica would "go down" and need to be re-cast if a spell successfully penetrated it. A magus would know when his Parma went down, but not necessarily why. (This is the opposite of the situation in ArM5, where a magus knows when his Parma blocks a spell but not when one gets through).

The effect of having Parma Magica as a ReVi spell was to strongly encourage all magi to develop their Rego and Vim scores. Presumably, this tended to reduce diversity among player-magi. Parma Magica was changed to an Ability in Second Edition, presumably to weaken the incentive for magi to specialize in Rego Vim.