Arts as Abilities

Arts as Abilities is one of the House Rules that are repeatedly brought up in Ars Magica discussion forums, although it is not clear if it is often implemented. The intention of the rule is to lower the scale of the magical Arts to that of Abilities. Instead of Arts using their standard experience scale (1 XP, 3 XP, 6 XP...) to set their level, they use the Ability scale (5 XP, 15 XP, 30 XP...).

If adopting this House Rule, there are probably a few other small changes that the players would want to make in rules that refer to Art scores. For example,

Teaching Apprentices

Replace the standard requirement of a score of 5 (15 XP) in all Arts with a requirement for a score of 2 (15 XP).

Writing Tractatus

Calculate the number of tractatus that can be written about an Art as it was an Ability.

Writing Summa

The troupe should consider whether they want to change the benefit of lowering a Summa's level for Arts to correspond to that of Abilities.

Puissant Art

The bonus should probably change to that of Puissant Ability.

Arts as Abilities lowers the scale of Arts, which increases the relative importance of other bonuses. It is thus a good house-rule if the purpose is to increase the use of such options. It also has the side-effect of greatly lowering the incentive to specialize, however, encouraging magi to invest heavily in Magic Theory instead of Arts.

If the spell levels are kept as-is, Arts as Abilities also serves to significantly lower the power of magi. This is often seen as an advantage by proponents of this house rule, as it brings magi more in-line with the power-level reflected in the game's background. In particular, their power still suffices to plausibly create the great magical feats and high-level spells of the Order, and to make powerful Longevity Rituals. Many players, however, prefer to play more powerful magi.

It is also possible to alter the spell levels by changing the scale of "magnitudes" to be x3 instead of x5. Thus a spell of 5th magnitude will have a spell level of 15 instead of 25. With this change in place, magi lose almost no power, although their Penetration is still severely reduced. The troupe should consider, however, how to apply this change to spells based on spell guidelines of level 4 or less. Calculating multiples of 3 is also generally harder and less fun, and while this house rule does make the system more consistent (with difficulties being multiples of 3 across the board and Arts and Abilities using the same rules) and encourages the use of non-Art bonuses, these advantages are rarely considered sufficient to make up for the increased hardship and vast overhaul required to apply this option. Arts as Abilities is therefore usually applied without this additional option, or not at all.

Prior Editions

Arts as Abilities was perhaps first offered by Michael de Verteuil in his column "Heretic's Corner" in the Hermes Portal fanzine.