You're reaching a bit.
A covenant is more than a single tower or building. The covenant is an abstract human construction composed of buildings and the people who dwell within. The charter might be closest possibility of being an AC, but I don't think it fits. And even if we did accept it was an AC to the covenant, it's still not an AC to the Aegis. ACs are links to a single thing at a time. They can change, sure...
Taking the devil's (i.e. ovarwa's) side for a moment:
I do think that the covenant charter, or any other item iconic to the covenant as a whole, would qualify as an AC to the covenant.
And if you have an AC to the covenant, can't you cast a Boundary spell to affect everything in there (of the appropriate Form), so e.g. a Perdo Vim ritual that dispels every spell active within the covenant?
I disagree, Fafnir. A covenant is a concept, a coming together of magi and mundanes, living together in a collection of buildings. Essentially, from a magical standpoint it is a T:Group.
An arcane connection only links up to a single, discrete object or being. Essentially, it provides a link to a T:Individual.
As such, the covenant's charter is simply a piece of parchement. It would be an arcane connection to the person who scribed it, just like any letter. That would fade within weeks, and unless it is handled frequently no other arcane connection would form.
YMMV
Ok, if we presume that the Charter is an AC to the covenant, would magi not cast spells on the charter that degrade how long it is an AC to the covenant? Wouldn't that be a security risk that any character within an Ars Saga world would understand and relatively easily defend against?
Important to note that Unraveling the Fabric of Vim unravels Vim spells, only. You have to switch to Wind of Mundane Silence to get all magical effects of all Forms.
What you propose now has a logistics element to it. The logistics aren't very hard to deal with under the mechanical rules of Ars Magica, but by unwrapping things such that you see what is required, it seems rather improbable to exist within the setting. First, we have to switch the spell under discussion to Wind of Mundane Silence, as mentioned above. To cancel all 30th level effects in a Bounded area, with any degree of certainty, the level of WoMS needs to be 60th level in level (I'm ignoring the results of the stress die, because it requires an investment and you want to be sure) before accounting for the Boundary Target. The Boundary Target would raise it to a 70th level spell (Room is +2, Boundary is +4. Since it's reasonable that one wouldn't want to cast the spell right next to the covenant, that would add another two magnitudes, going from 70th level to 80th level, to cast the spell at R:Arcane connection, rather than R:Voice. An 80th level spell requires 16 pawns of vis to cast. Requires a person with a lab total of 160 to invent it in a season, 120 to invent it in two seasons, 107 to invent it in 3 seasons or 100 to invent it in 4 seasons. It's not hard to get a lab total of 100, but it does require a certain amount of dedication and focus. Since the WoMS needs to have a penetration of 30 to overcome the level of the Aegis I suggested above, that means the caster needs to have a CS of 110 in Perdo Vim. So the confluence of the necessary casting Score and lab total suggest it took 2 to 3 seasons to invent such a high level spell. Not impossible, but against a PeVi specialist, such a high score becomes really unlikely, because why...
All of the figures above are done off the top of my head, without a lot of effort expended in checking my figures or changing my assumptions. Again, the exercise, even if I'm wrong in an underlying assumption, it isn't going to be off by much, suggests that such a spell doesn't exist, nor does a person who could and would cast it.
Oh, and if memory serves (serf's parma), it is only a 10th level spell to degrade the AC on an item by 1 level. It can be cast repeatedly so it is not an AC with very little effort by virtually any magus within the Order of Hermes...
Doesn't work on permanent AC.
Wasn't aware that letters were permanent ACs...
But, the number of permanent ACs are remarkably few and none of them appear to point to an entire Covenant as a legitimate source...
You can spend a season to turn any AC into a permanent AC.
Ok, you're really reaching. Yes. Of course. Anyone who has the Gift, a pawn of vis and access to a lab can make any AC permanent. No argument there. But you've tried to change the argument from whether a charter can be an AC to the covenant, to the issue of one fixing an AC, when that's not even up for debate. I'll take your original contention, about the charter being an AC to the entire covenant at face value and break down the fixed AC issue, even though I find the premise to be, let me repeat, a reach.
If we posit, within Mythic Europe, that the Charter to the Covenant is as an AC to the entire Covenant, you don't think that the magi of the Order don't know this and understand it? And if they do understand it, wouldn't they take steps to prevent it from being an AC to the covenant, using that 10th level spell, as I suggested? And wouldn't that happen before anyone had an opportunity to take the Charter to their lab, and make it an AC, since that takes an entire season, while the Charter's connection to the coveant can be severed in less than 30 seconds.
Hi,
Someone sounds unhappy!
Look, I'm not saying that any given X should be an AC to a covenant. But I am saying that I recall precedent for something being connected to something as abstract as a covenant (which is made less abstract by its having a Boundary, right?) Wasn't there a Story Seed involving a charter? Regardless. I think that one can have a sufficient AC to an Aegis, but if someone decides otherwise, fine. I thought we were already past that.
But if an AC can be found or enhanced, then you're reaching too, because the magi would have to account for every possible AC and diminish it as you describe.
Well, anyone whose Hermetic Arts have been opened at least.
Not changed the argument; I believe I've acknowledged that it's up for debate. Ah, here's a sample of me Not Arguing that the Charter Must be an AC:
"It would have to be a pretty good AC, I'd agree. A random clump of dirt, no. But the covenant's charter? A piece of the tower's cornerstone or the council table? Maybe."
So, Maybe.
Maybe it is a reach. I admit I'm of two minds about it, and can see the argument either way. An AC isn't necessarily something that was once part of the original, but also something that has an extremely close association. So my favorite sword can be an AC. Not a reach! Why not the cathagh (sp?) of an Irish covenant, by dint of its being necessary for the function of the covenant and by dint of the effort the covenant spends guarding it?
Just saying.
Personally, I find this far more appealing than magi having to be be careful of every stray hair or stool. But again... Maybe.
Of course. But there might be 50 other things that are ACs to the covenant. Also, if the covenant continues to enshrine and guard and be constituted according to its charter, than the AC is renewed. Sort of like my destroying the AC to my favorite sword without destroying the sword... and then I keep using it as my favorite sword.
(As an aside, in a spiritual, magical, mystical sense, it must mean something when an AC is dissolved.)
And then possibly renewed, per above.
I admit that I'm warmed by an actual argument about what real magi might actually do.
I also admit that I'd love a reworking of what ACs are and how they work; I've written about this before.
Coming back to the original issue, though: If I have an AC to something that is affected by a spell, is that sufficient for me to have an AC for the purposes of dispelling the spell? I'm saying Yes.
In the case of an Aegis, I don't think I even need the charter. Because once granted that Yes, an AC to any part of the covenant that is affected by that spell is sufficient for me to PeVi the spell on that part, and since there's only one spell, that dispels the whole thing.
Anyway,
Ken