When Aegis of the Hearth is recast, does it expire in between, or can the
new one be cast prior to the old one expiring? (Or in a way that makes
the transition seamless.)
In either case, if an supernatural creature is inside the boundary of the
Aegis when it is being cast, it will suffer the Casting Total Penalty, but can
remain inside the boundary indefinitely, right?
Would it be possible for such a creature to participate in the ritual of the
Aegis, or can only humans participate in the ritual?
Assuming that participation is possible, what about covert participation?
Assume the ability to masquerade as one of the legitimate participants;
would the ritual leader know something is wrong?
In case of demons it seems clear that covert participation is perfectly
doable if participation is at all possible, given the powerlessness of
Hermetic Magic in the face of infernal lies, but would a fairy or a divine
creature be able to do it?
Personally, I maintain that, due to it's mercurial origins, the ritual must begin at noon on the solstice. Therefore, there is always that time every year where the Aegis is "down" for a short while, while the new one is being cast. This has allowed for some interesting planning on the part of my players to make sure that they are defended correctly during the casting of the ritual.
As it is written on ArM5 p.161, the Aegis lasts until sunrise of the fourth equinox or solstice after its casting - customarily the winter solstice. Magi renewing it should be able to complete the ritual for the new Aegis before sunrise on the winter solstice, leaving no time when neither old nor new Aegis are up.
Of course, if they are disturbed during the casting of the ritual, it might be finished too late ...
As written, only magi and non-Hermetic wizards can participate in casting the ritual. The latter is an ill-defined term, open to all kinds of interpretation by SGs out for strange plots.
Zurenzialle - the Faerie who posed as a magus - might have participated in many Aegis rituals without being noticed, or might have lived alone and apart from covenants. But then Zurenzialle was a very special Faerie.
Declaring every demon to be a non-Hermetic wizard is too far-fetched however: that their lies are impenetrable by Hermetic magic in no way implies that they can function as magi. So even if their participation in an Aegis ritual is unnoticed, this does not imply that it grants them immunity from it, or powers to invite/expel other beings into/from it.
The place I inferred the possibility of non-magi participation was the "entire convenant usually participates" bit, as it reads as if, for example, non-magi Redcaps are expected to be able to participate. If taken this way, then the participation is more along the lines of "be there, hold a stick of incence, and shut up" so that the Aegis will be attuned to the participants.
...but maybe that is reading more to the text then there really is.
The other interesting bit is enchanted devices: they need to merely be within the Aegis when it is cast. Unfortunately extending it to supernatural beings seems bit of a stretch. What about familiars? I thought there was a specific rule about Aegis and familiars, but I can't seem to find it anymore.
Familiars are bound to their Magi...that seems to provide them with a distinct "in".
I look at it more along the lines of a blessing. The Magi asks the participant to speak his name, then pass their power through said individual. This brings that person into harmony with the Aegis....which brings up another point..
Most Aegis are cast without Penetration...how would it affect a Demon? Said creature would have to allow it to happen...If the spell is more like a blessing (like I said above), then this could possible be a problem for the demon in question...
I don't think it likely that any demon could do this...if this was the case, then it would be SOP for demons to do so, and the Order would respond or have been destroyed...
Aegis is already a bit of a special case wrt. Penetration: it unconditionally stops creatures with less Might then the Level of the Aegis. OTOH, I can see how you could say "yes, but to affect someone already inside when it is being cast you need to penetrate"... Forget about participation in the ceremony, just hide and hope the penetration is low enough!
That could work -- for me, at least ,-)
Allow covenants to recast the Aegis without having a vulnerable period in between.
To affect someone already in when the Aegis is recast it needs to penetrate. Should that someone leave, they will be subject to all the normal penalties if they return -- if they are even able to return. If an uninvited guest is already under the influence of the old Aegis, they will also automatically be under the new one when it is cast -- no penetration necessary in that case.
So newly founded covenants would need to think about establishing their Aegis a bit:
Better start with a smaller boundary, so you can better check that no uninvited guests are lurking in corners.
It is probably best to cast initial Aegis at level 10 with penetration 10, rather then just level 20 (or whatever), to hinder the ever-present minor demons, the kind you can't help hittin when dropping a pin from the roof...
All in all, not horribly onerous, but makes building a mystically secure covenant slightly more involved then just "we cast Aegis" -- and leaves
potential way in for enterprising minor entities... if they manage to hide for the initial casting and can resist the Aegis. Operative word being "minor" here: this way a covenant can be haunted by something less horrible then what would actually be required to ignore the normal Aegis.
OoH is certainly aware of the "loophole", but there is only so much you can do about it. As far as story hooks go, it also gives a good reason for eg. Quesitors to keep an eye on new covenants, no matter how upstanding their inhabitants are: "It's a new covenant, so they could still have something hiding under the Aegis..."
Another question: what happens if a portal or regio entrance is within the Aegis? (Like in Durenmar, IIRC!) Do you need to be invited on the far side to pass at all, or does such a method of entry bypass the "border", so you are only hindered by the Casting Penalty if uninvited?
Yes, I should think so. By the description of the Aegis only magi and non-Hermetic wizards can participate in the ritual creating the Aegis, and hence thereafter can give and withdraw invitations into it, and are not hindered by it in their spellcasting. "The entire covenant" mentioned in the text is the same who often "holds a major council meeting ... after the ritual of the Aegis" - hence consists of sodales, not covenfolk. Others 'participating' in the ritual as bystanders - holding the cloak of the ritual leader, some incense or their noses - may have some warm and fuzzy feeling of belonging afterwards, but no powers over or protection from the Aegis. This should hold also for non-Gifted Redcaps, who, while sodales, with respect to magic are just mundanes.
Demons could of course always exercise their considerable 'social engineering' skills (subterfuge, disguise, threats, blackmail, seduction or bribery) to be given a token and invited into the Aegis.
I am not aware of any rule explicitly and specifically about familiars in an Aegis. But a magus always can invite his familiar into the Aegis he helped to create - so we need not look the books up and down for this.
(Often a familiar also will have been bound within the Aegis by a magus who participated in the ritual, hence one could argue that the rule about magic items created within the Aegis applies to the familiar in this case, too.)