Can Wind of the Mundane Silence work on Aegis of the Hearth (or any PeVi) to bring it down ???
Since it can bring down Parma I thought it can also affect Aegis ??
Thrumbar
Wind of mundane silence has a room target, which is very hard to use against a effect usually found outdoors... But apart from that - it's a spell, and can be dispelled...
I think you need a ritual spell to counterspell a ritual spell. 
What makes you think that?
I've never heard of this, but it could well be possible, so please quote references if you can find them, thanks.
Corbon
Herm i misread this with magic items 
But im sure there is a rule concerning this O_o
Was thinking about it as the following way
Winds of the Mundane Silence
50 Pe Vi Range: Voice Duration: Mom Target: Boundry (R)
The spell must penatrate the Aegis to have effect. If the penatrated, and
it's level + stress die is double the Aegis level x 5, then the Ageis is
dispelled. You must trace out along the boundry of the original Aegis
ritual to dispell it which may leave you open to attack.
(base 20, +2 Voice, +4 Boundry)
Thrumbar
With a Boundary Target it have to be a ritual spell
With a bountary target you'd affect EVERY magical effect within the Aegis...
Sounds like a major overkill to me...
I'd say an individual target should be sufficient, but you probably need some way to either detect the Aegis (you can't usually see it...), or one of the keys (since they would act as AC to the Aegis...)
There is nothing in the rules to stipulate that ritual magic can only be dispelled by further ritual magic. That said, I might insist on the spell being ritual in this particular case, were it to come up in a game I was running.
A Wind of Mundane Silence is unlikely to bring down even a moderate Aegis of the Hearth, however, since I presume that the Aegis itself benefits from its own protection. Even an Unavelling the Form of Vis spell would be unlikely to work, given this.
What the would-be Hermetic beseiger requires is a spell specially designed for knocking down the Aegis. Siege of Apollo in the Mysteries would be one example, but it's rather overcomplicated, and suffers from more or less the same problems as Wind of Mundane Silence.
My suggestion, as such, would be as follows:
The Wizard's Arbalest PeVi Gen
R: Sight, D: Mom, T: Ind, Ritual
This spell will dispel an Aegis of the Hearth whose level is less than (spell level x 2) plus a stress die. The spell still requires a sufficient penetration total to defeat the Aegis to be effective.
Base effect as Unraveling the Fabric of [Form], +2 from Voice to Sight (hence the loss of the +10 to the spell's effective level). Difficulty halved for a spell so specific, following the rationale that a dispel effect specific to one form is twice as effective as one general to all arts (i.e. Unravelling the Fabric of [Form], compared with Wind of Mundane Silence). The need to penetrate the Aegis' magic resistance essentially means that, though the spell need not be learned at a veryhigh-level, its caster must be fairly proficient in Perdo Vim.
Does that make sense to people, or am I misreading the rules. Or just thick.
looks like a good spells to me.
Ta very much.
I would just wonder if it would not be better to make this an arcane connection spell.
The advantage of arcane connection spells are that they are very good against things like magic might or magic resistance because you can use the rules for sympathetic connection as a multiplier on your penetration ability.
It also makes for some interesting story elements as magi of a covenant would be less inclined to disclose information like the exact date of founding and exact location ( a horoscope could be done on the founding with this information ). It also means magi would be really worried if someone started carting off some of the stonework, tableware, or a tapestry from the covenant. 
I've been pondering this... would a magus involved in the Aegis ritual work as an arcane connection to the spell? Since they can resiliate tokens, are un-hindered, etc, it seems that there is some kind of connection left.
And would an (unresiliated) Aegis token act as an arcane connection to the whole Boundary covered by the Aegis?
Could get pretty bad... 
Salvete Sodales!
I don't see a reason, why such spells (with or without arcane connection) should not work. I haven't checked on the rules for details of the formula, but assuming they are correct, I wonder what other magi in the order might think about a magus developping spells to turn down Aegis rituals. Nearly like the Parma the Aegis guarantees the safety of the order by keeping the mages from each others' collective throats (and by turning hedgies powerless in direct confrontations). This spell would be directly designed against this foundation of the order's strength, sometimes useful (e.g. in marching a powerfull wizzard), but I would become pretty worried about a magus who devellops such a spell, unless I had a really good reason to trust his motives. The Guernici might feel the same.
Vale,
Alexios ex Miscellanea (aka Lars Gerlach)
Thanks for the feedback, I'm glad people seem to think the spell makes some sort of sense as I've devised it.
Regarding Alexios' post, I'd be inclined to see the spell as being something of a closely-guarded secret, perhaps, like the Aegis itself, incorporating Mercurian or other pre-Hermetic magic. It would be a secret known only to, say, House Guernicus and a select few Hoplites, and probably unused since the Schism War. It would be the ultimate 'big stick' to compel loyalty and obedience to the code among the order. You're certainly right to suggesst that, since the Agis and Parma Magica are so important to Hermetic unity, it's not a spell one would want to fall into the wrong hands. Since most players would be unlikely ever to think of it, it could provide a nasty shock for them to see it wheeled out in response to some crisis.
In reply to PhiliAtlas' suggestion, possessing a token connected to the Aegis in question would certainly be very useful for the caster, allowing a better penetration score. If I recall from some of the descriptive text in previous editions, the Aegis ritual was supposedly usually performed on some day of magical significance like the Midwinter solstice, so discovering when it was performed might not be so difficult. I'd be inclined against giving it the range of Arcane Connection, though, purely on grounds of practicality.
What this now sets me to thinking is whether it might not be possible, working along the same lines, for a spell to knock down a magus' Parma in a similar way...
Personally I'd say since the aegis isn't strictly hermetic it would take a break through to create a spell to destroy it
While I think this spell is a great concept, I can see some problems...
If this spell was possible, someone WOULD make it...lots of someones. It would become general knowledge in about, oh, five minutes. With all the various squabbles going on, it would seem likely that a powerful magus would use this spell to 'whack' his opponents Aegis, where he thinks he is safe, and attack him unaware. This of course would remove the protection around everyones Covenant (the threat would be the same as any real danger), causing Magi to attack first out of fear (remember those days before the Order?) Things would degenerate rapidly from there...
From a realistic standpoint, I think this would be tough on the game setting...
Suggestions:
- Major break through. This doesn't solve the above problem completely, but does slow the timetable down to about twenty minutes...
- ...Because its dampening effect on magic, any attempt to dispel an Aegis results in the caster needing a casting total: Aegis Level*3-Aegis penalty. The spell should certainly be a Ritual due to the complexity and level.
- Tokens: Tokens are used to allow someone Inside the Aegis, who has permission, to cast a spell without a penalty. Tokens taken outside the Aegis lose their connection to the Aegis. This would be similar to breaking a Ring spell for a subject inside it.
I am a little shakey on how you can get an AC to a spell...
AC's are physical connections to physical things (or things that once were) IIRC
Agreed, I wouldn't dream of letting my players invent anything like it. As a Storyteller, I'd probably rule that, like the Aegis itself, it was a relic of Mercurian magic, and as such more-or-less impossible for a player character to invent. In the context of the game's setting, I still think it could be interesting and appropriate; it would provide a neat explanation of how whole covenants, like those of the Diedne, or various others mentioned in the background, might be marched by the Quaesitors and their minions. It's certainly the sort of capability to which one could imagine House Guernicus would want to have access, provided, of course, that they alone possessed it.
The dampening effect of the Aegis, however, is, in theory, accounted for in the design, by the necessity that the spell when cast have a sufficient penetration (i.e. (casting score + penetration) - spell level) score to overcome the Aegis anyway. This would, in theory, ensure that only very potent magi would have the capacity to make successful use of it, even though the spell itself would not have to be of a very high level. I would agree it should be a ritual, if only to ensure that it's a more serious proposition to cast, and to fit with the notion of Mercurian design.
With these caveats and restrictions, I think it is a not-unreasonable use of the rules. That and the fact that, now I've gone to the effort of thinking about it, I'm quite taken by the story possibilities of the idea.
So am I. In fact Fruny's conjecture opens an interesting can of worms about whether a magus has an arcane connection, and vice versa, to spells he has cast, at least while they remain active. I'll let someone else answer that one.
Not in most cases. If the magus has the Tethered Magic virtue, or the Fettered Magic flaw, then yes, all his spells are arcane connections. But the Aegis is special in that the magi that were involved in the ritual can remotely "disenchant" the tokens. This indicates that some connection is left between them and the spell, though it may not necessarily be usable as an arcane connection (unless you decide it is ).
Just a couple ideas worth investigating. 
I take it that Tethered Magic and Fettered Magic are from splatbooks, I don't recognise either of them. If the question is answered with their descriptions, then that sorts that out.
I'd be inclined, admittedly without having thought that much more about it, to rule that the tokens would constitute arcane connections to the Aegis, simply for the story possibilities offered by the player characters having to obtain one. As mentioned earlier, the non-Hermetic nature of the spell makes the rules position less than clear.