[quote="ezzelino, post:62, topic:169976, full:true"]
I would disagree slightly with this. I think that Aegis and wards should definitely be type 2, i.e. move attached to their Container, and affect valid targets within that Container for as long as they remain within. So, if you cast an Aegis on a covenant, and during the year you build a new hut within the covenant's boundary, the hut is protected.[/QUOTE]
We don't disagree on this. I just didn't state my position as well or as completely as I could have at the time.
In brief: If you wish to add "another building in the middle of the covenant" with the Aegis existing further, you need to cover that hole with the Aegis.
Now rewrite the rules, so that this still verrry handwavy description really happens. This is not easy at all - and likely beyond even generous errata. Turning it then from handwavy to executable - without allowing abuses like the Aegis of assault - takes a lot more effort still.
For now we have instead (ArM5 p.113):
The spell affects everything within a well-defined natural or man-made boundary.
This is sufficient, if you make sure that boundary applies only at casting time (type 1 spell) to define what "everything" means. If you consider to move it, the logical consequence becomes LoH p.123 box A Note on Boundary Effects:
Boundary effects are not, by their nature, mobile.
Immobile Boundaries doesn't actually solve the problem because it exists for every container Target, not just Boundaries, and really no one, not even the anti-mobile-Aegis lobby, wants to completely cripple the ability of the multiple canonical ship-based covenants to do things. You know, with their floating Structures full of moving Rooms.
Aegis of Assault feels like a very silly expenditure of resources when you can pop an Aegis with a formulaic spell or (the munchkin's preferred option) a disgustingly-high-Pen charged item. Sure, inflicting a casting debuff is potent, but...a powerful ritual, an absurd amount of setup, and whatever time, vis, and effort is involved in building and enchanting the mobile boundary gimmick versus one formulaic. Obsessing over this particular bit of blatantly un-Mythic munchkinry feels like a severe prioritization error.
Using the Aegis of assault on an adventure site (just for an example think TTT p.107ff The Spider's Game, esp. p.114ff A Grisly Fate) does usually not need to expect a Wand of assault to counter it.
Magical tactics to assault another covenant are typically involved, tricky and expensive: taking over that covenant's Aegis and landing on top of it in just two rounds is bound to turn it into a disorganized ant-heap or worse. Worth many rooks of vis for sure!
Yes, and? Wards, like Aegis, are explicitly of the first type, and I cannot imagine a world in which a shipboard covenant doesn't want to ward its facilities against water, fire, and rats.
I'm just mentioning this to dot the i's and cross the t's, but The Bountiful Feast has a weird boundary that is defined by people who own the fields participating in the ritual, but that noone has to trace the boundaries at casting. I'm not sure how this might affect the discussion, but I wanted to draw people's attention to it who might be less hung-over than I am right now.
It is not sufficient.
Remember. a courtyard is canonically a T:Room. So I cast a D:Sun, T:Room spell "of type 2" on a courtyard. Not a ward! Say, a ReAn spell to make animals tame and nice. Then, I teleport the four walls of the courtyard 1 mile to the south. Does the spell stay where it was? Does it move with the walls? Does it vanish?
So you have to address, for all containers (in the technical sense of T:Room, Structure, Boundary etc., exactly what happens when the symbolic perimeter of the container moves. I think there is no clear, rigorous answer, just like there is no clear rigorous answer to the question "is a ship still the same ship if I tinker a lot with it?".
The answer depends on how "essential" that concrete object representing the perimeter of the Container is to the Container. The plaster on the outer walls of a courtyard can be easily removed without any T:Room or T:Boundary spell being affected. The same does not hold if the walls of the courtyard move. But in the vast majority of situations, there will be an easy-to-reach consensus.
The title and the OP of this thread talk of Aegides. They are for now T : Boundary.
So you may allow me to consider in this thread just arguments regarding Aegides and rules regarding Boundary targets - and not to anticipate, that your interest goes beyond them also to T: Room. OK?
No. Because this thread is about stuff that specifically regards the Aegis (on moving Boundaries).
If there's some issue about ... Rego, say, that affects every Rego spell, it should not be addressed in this thread by trying to find an Aegis-specific patch. It should be addressed for all Rego spells, in fact ideally before any Aegis-specific discussion it might have an impact on.
In that case, you should perhaps just introduce your contribution by an explanation, just why your point of interest is relevant to this thread, instead of with:
OK?
Also, a courtyard can be a lot of targets. e. g. T: Ind, T: Room or T: Boundary.
This might belong to another thread, because you first have to sort out, whether the courtyard - as T: Room - needs to have a floor and you hence destroy it with the teleport of its walls.
Best start with:
So, you decide to teleport the courtyard with both floor and all walls, then the type 2 spell with T: Room might move with it.
The only "symbolic parameter" among them appears to be the boundary of T: Boundary, which (ArM5 p.113) "affects everything within a well-defined natural or man-made boundary". By (ArM5 p.135f) The Bountyful Feast, such a boundary can be a set of property markers or even property deeds.
Does selling/buying new property then change the boundary of the area, as soon as it is documented?
EDIT: Could then a canny magus, whose covenant's Aegis is linked to the deed of its area, just buy the land another covenant is built on from its rightful owner, then destroy that other covenant's Aegis with a Wand of assault, and at nearly the same time perform the last stroke of the deed joining that other covenant's land to his own covenant's? Would at this monent the other covenant's Aegis be replaced by that of the canny magus' covenant?
I think you ask what it is you want the end result to be.
Now, I would like it if covenants that inhabit ships and caravans are as well protected as those sitting on bedrock.
And therefore I'd say that no Aegis may penetrate another. The moving Aegis will just bounce. If I wanted to be doubly sure I'd say that they can't even approach another Aegis closer than a couple of miles.
The spell isn't well understood or reconciled to Hermetic Theory. It can be as quirky as we need it to be.
I'd also argue for a minimum size of Aegis larger than that which can be carried as a personal item.
I'm sure that in this great mass of speculation there are reasons why this Cannot Possibly Be but I ask the story based question again. Do you want it to be possible for there to be a mobile Aegis? If so don't bring up world wrecking possibilities. There are enough means for the Magi to break the world already.
If we can distance ourselves from just errataing in a mobile Aegis, we may be able to introduce sufficient rules to have a mobile Aegis in some sagas, based on new Ars Magica 5 contents.
We need some new rules. Perhaps around a new Target replacing T: Boundary in a variant Aegis, which is not accessible to just anybody and brings its own limitations. Or a way to enchant an Aegis into a vessel, thus turning it into an enchanted device and thereby invoking all the limits on expanding and disassembling it.
So I am speculating about a new Legend of Hermes. A seafaring follower of Notatus and Seeker of the wisdom of Atlantis, now buried with their vessel at the bottom of the sea.
There is a legend about a variant Aegis protecting it! But where is it sunk, and what remains of it? What did its creator find on its last voyage?
There may be whispers, that our Seeker found the pre-Hermetic mystery of the protections of the Paralus, studied them, incorporated them into their own vessel and then embarked onto its last voyage.
The Aegis of Assault has horrible aesthetics, and should not be possible for that reason.
I'd note that warding a ship against water would stop you taking drinking water aboard; better make it a bit more specific. And be prepared for the Warping.
There is more story potential in @OneShot's idea of characters trying to create a Aegis they can use with their ship-based covenant than there is in simply saying that it is already possible.
Another bit of bad aesthetics: Wards do not exert force, so a circle ward passing over someone does not move them. However, if you can drop it over them, as if this were some sort of hoopla stand, they cannot leave. There are easier ways to paralyse someone, so this is not a balance problem, but, as I say, I really don't like the aesthetics.
Mind you, I'm not really fond of the aesthetics of orphaned Aegides floating in space…
I feel that something like this is correct. We don't necessarily need anything more precise than that; we have coped without for 17 years, after all.
the fence represents the perimeter, but is not the perimeter
magic is all about symbolism.
As such you should be able to alter the fence to alter the perimeter (perhaps with a ReVi spell involved), but it should not allow you to simply pick up the fence and redefine the boundary.
The other thing I keep having images of is ancient (like ancient Greece) naval battles which consisted primarily of ramming two ships into each other until one of them breaks.
If we go by this (and I'm not opposed to this), anything crossing a ring/circle, breaks it.
Yes, that explicitly includes a blade of grass falling across the line.
That is a traditional way of symbolically 'cutting' a magic circle.
