Magic Resistance mastery and the Aegis of the Hearth

Games Discussion Ars Magica
91

I will answer from my groups arrived on consensus, even though in some places I disagree with it (though I will note where).

  1. Currently my group plays that external "foreign" magic items must penetrate the Aegis and and internal ones suffer the reduction to Penetration. Though truly this is something I disagree with and should be added to the "How Does Aegis Work?" thread since it means only those with MR are protected from internal "foreign" magic items.

  2. The Aegis reduction to Penetration effect works on magical creatures (beings aligned with the Realm of Magic or beings aligned with all Realms depending on interpretation), not just beings with Might. While Powers were not codified until after the varies Realms of Power books came out, this is what the effect is targeting. Innate magical effects which have a Penetration Total but no Casting Total. The power a Magus gains from Mythic Blood is a Power and thus suffers from Penetration Reduction. Skinchanger (and similar) are unaffected because we could not settle on something that did not completely block them. The closest we came was getting a positive result on a Sta + [Realm] Lore Ability - Aegis Penalty roll (with the Realm used being the one the power is derived from). This is something I pushed for since it made things like Skinchanger similar to Heartbeast.

  3. We require already cast spells to be able to Penetrate the Aegis when crossing over into it. We view the external spell on someone crossing the boundary the same as casting from outside to inside, making no exceptions for spells on beings with MR. While a being with Might might be able to cross the boundary, all spells on them that cannot Penetrate the Aegis are stripped. The Parma Magica however is not stripped, since we ruled the Aegis is a "Parma Magica of Place" and two Parma Magica coming into contact will not negate each other.

  4. LR and the cords of a familiar are part of the beings essential nature. The LR for example cannot be dispelled (this was an official ruling). The cords of a familiar are also not suppressed, though any effects enchanted into the bond are resisted the same as an enchanted item. Note that effects in the bond are activated by the member they do not effect which if one is inside and one outside becomes important.