So in the interest of making Winter covenant defenses, ofwhich the old magi basically relied on difficult access, being on a island, and magic to protect them from any mundane or supernatural dangers, I came up with a item which I can't determine the size of.
Mind you this is a item and it uses a Mystery virtue to bind a earth elemental to power the Ritual spell, the question is how big!
Following the wall of a covenant, a massive wall of smooth granite grows from the ground. At 7 paces (21 feet) high and a pace and a half thick at the base, few enemies are not overwhelmed by the instant appearance of such a formidable obstruction. The walls are smooth and offer no edges or protrusions for scaling the massive heights, and extend a pace under ground to thwart tunneling.
Although I also made the Lvl 40 spell to make the size +2, just in case it is felt that you would need a extra size to provide for such and abundance of granite. I just cannot determine if you need the extra size for the increase of stone and distance or not. At size +1 it already allows for a lot of area and stone to surround that area, but an additional size modifier would not change the amount of vis that is required by that much, so would not be a issue especially for a Theban covenant and for a item powered by a spirit. ((sure a higher might spirit would be a issue but only if your storyteller insists on being such a nit-picking munchkin of rule-doom.)
So should I leave it at 35 since it is after all a mighty Ritual with Boundary target already, or throw in the extra level size modifier?
The same Guernicus Earth magic specialist, would also probably make a spell that either sprouts hands from the ground around the walls or from the walls themselves, that grabs and smashes attackers. I had imagined the items would be small stones or pebbles that grogs could toss to the ground and where ever they land a massive stone arm and hand would sprout and begin attacking any in reach.
First thing I see is that you have the Target as Boundary (+4), which is by definition a Ritual spell...do you really want to spend 7 or 8 pawns of vis for something that's only going to last half a day?
I would call it T: Individual, since you're making one wall, and then depending on how big the covenant is, tack on a few Size Modifiers. With your size of 8 paces by 1½ pace per pace of length, you're looking already at a +2 Size Modifier for a 1⅔ pace long piece of wall. Each 10-fold increase of length adds 1 magnitude.
So. Base 3, R: Touch (+1), D: Sun (+2), T: Individual, +2 for Size, makes it a Level 20 for a monolith 8 paces high (including the 1 pace below ground) by 1½ thick by 1⅔ long. Level 30 makes it 166⅔ paces long, Level 35 makes it 1,666⅔ paces long (which is 5,000 feet, or just under a mile).
I'm intentionally ignoring the Mystery Virtue to bind the spirit, because I don't know anything about how that works, and can't be bothered to track down where it is to research it
Peregrine_Bjornaer is correct: the spell should be Individual, rather than Boundary (incidentally, remember that Creo spells that create stuff can only be T:Ind or T:Group). So, no need for a Ritual!
I just liked the imagery of the item being set into the small retaining wall of a run-down covenant, and then with just a word it sprouts a massive nigh=impregnable wall following the small flimsy wall. Of course it is easy enough to do the same effect with T: Ind and size modifiers, and make the spell follow the wall.
Wouldn't that be a Muto effect? Ah, yes. Muto Terram, base 4: "Make something grow to eight times its previous volume." Perhaps with an additional magnitude for each multiplier. And with a Rego requisite to make the expanded volume take the form of reaching, grasping hands and arms?
Figure of speech. The actual low wall of stacked stone would not actually turn into a wall of granite. The spell was just going to create a massive wall of granite that followed the exterior of the miniscule retaining wall.
My ending spell which I think will work to cover the amount of area required (half of a craggy cliff, the other half not even climbable) and does not contain the boundary target is as follows:
Covenant's First Defender
Lvl 40 Cr/Te
base: 3, R: Touch +1, D: Sun +2, T: Ind, +6 size
Following the exterior wall of a covenant, a massive wall of smooth granite grows from the ground. At 7 paces (21 feet) high and a pace and a half thick at the base and tapers to just under a pace at the top. Few enemies are not overwhelmed by the instant appearance of such a formidable obstruction. The walls are smooth and offer no edges or protrusions for scaling the massive heights, and extend a pace under ground to thwart tunneling.
This spell creates 1,000,000 cubic paces of granite, which makes the parameters of the wall 7 paces high, by 1.5 paces thick, with a radius of 200 paces. Though it actually doesn't hahahah those measurements seem to give a curbic area of 1,321,300 but what is a few hundred thousand cubic paces amongst friends.
Besides I figure if the thickness averages out to a pace or a bit more which gives the actual area between 880,000 cubic paces (1 pace thick uniformly) to 1,321,300 cubic paces (1.5 uniformly) in between the two is being a bit over 1,000,000 cubic paces.
The best part being this is put in a item, with enough penetration to basically thwart any attack below 6 or 8 magnitudes!
Hmmm, 7 paces high, by 1.5 paces thick, by 2pi200 paces long is less than 13.200 cubic paces, not 1.32 million cubic paces. You are overestimating by two orders of magnitude, so you can drop the spell level by 2 magnitudes.
I know I am sleepy and have so very little practice in daily life with math but in the equation I do, it works out every time to 1,32 million. Then I realize I am working out the area.... well then much much better.
PS. Amazing where a misplaced squared function will take your calculations... well yeah, it squares them.
The only need it could have for penetration is to squash or push out of the way creatures on the boundary when it appears. As a wall it is passive rather than active, not doing anything to be resisted. It still has substance and a creature with MR can hurt itself by hitting it.
