I like the section in Transforming Mythic Europe regarding the Hermetic Island, with the surrounding walls. The number crunching was especially welcome. I have a few questions though.
If you were to design a circular wall 30 paces high and X miles around, one of the 30th level spell examples let's say. If you were to make a ritual that healed/repaired the wall would it likely be the same level just for sheer size? I might be doing the math wrong, but at Base 3 to create it, it would likely still be Base 3 to repair it, and then from there it's the same added levels for Touch and Size (+1and +6). So in essence as powerful a spell to repair as it is to create it. There are other options of course, but that would be required, right?
The other option they mention is giving the creation Ritual requisites, one was a wall that perpetually burned, but then they had a wall that healed itself and the requisite (plus a magnitude or two I'm sure) of Corpus, Animal or Herbam, allowing the wall to heal like a living thing. What kind of time frame would that be like? Would it require Recovery rolls? Would it always (but gradually) restore itself given enough time, and would it need material to restore itself (like stone or earth)? Would it benefit from Recovery bonus conditions (from magic perhaps) as well as maybe skilled masons?
I like the idea of the healing wall, it provides some interesting questions and problems all its own. Just thought I'd see what people thought.
I believe Magi of Hermes has a CrTe 15 guideline. However it is NOT a ritual! So it can be put into an item!
Consider the item:
Mason's Eye - 24
R: Per D: Constant T: Vision
This spell gives the item a sense of sight. The item can "see" damaged sections of stoneworks, and determined how much damage it has sustained.
Base 2 +2 sun +4 vision +4 constant
Tireless Mason - 48+
CrTe - unlimited uses
R: Sight D: Mon T: Part
This repairs the targeted section of wall returning it to a "new" quality. This spell triggers on the greatest amount of damage it can see. As it has unlimited uses it will constantly be repairing damage.
Base 15 +3 sight +1 part +x size +10 levels unlimited uses +3 levels linked trigger
Stick this at the highest point of the island. It will constantly repair damage. 10 times a minute, 600 an hour, 15,400 a day. Depending on how big the size modifier, and how big the size of the walls/island it can get everything within a few days or years. And of course, you probably need to place it high on the island so it can see everything!
How do you convince your troupe, that 'the item' is a person to bestow a Magical Sense upon it? ArM5 p.113f Magical Senses: "Intellego spells can grant magical senses to a person. ...". Items sensing tmk work with different guidelines: see e. g. MoH p.32 InIm Read the Words in p.31f Dico Calculus, or some effects in Aurulentus' items (p.23f).
I can think of a few ways of achieving such a self-healing wall.
One of the more interesting, to me, is choosing not to actually make it permanently at all.
For instance: The Impenetrable Wall
Creo Terram item 38
R: Touch, D: Mom. T: Ind (+5 size categories)
Makes a wall of granite up to 1000 paces wide, 20 paces high, and 5 paces thick; every 6 seconds. As the wall itself lasts for only six seconds, all attempts to damage it are entirely fruitless.
(Base 3, +1 touch, +5 size categories, +10 levels for infinite uses, +3 for environmental trigger [to ensure that it triggers continuously])
Just spread a few of these out around the island to produce an utterly impenetrable wall, that can be turned off when you want to pass through it.
EDIT: If you don't like the interpretation that momentary lasts up to 6 seconds, you could instead go with diameter, for an extra 5 levels.
This reminds me of an effect on a sword and shield in the Broken Covenant of Calebais, but its duration is Sun with 2 uses and enviromental trigger, CrTe. It didn't need a sense though. And actually at this point it's been stated that items don't need to sense things (like giving an item the ability to hear so it can respind to Shriek of the Impending Shafts and trigger another effect). So maybe an item like a keystone brick implanted into the wall, with a range of touch doing a constant repair job? That could work.
You could also do a keystone brick. A lot of ways to get this done. The idea behind this is it only targets the sections that need repairing, and it keeps the size down. In three years you could get 10,000,000 cubic paces or rock repaired. Heals pretty quickly if the wall is under attack too. It can't make material, but in Mythic Europe rock grows underground! (I think?)
What about the Requisite of either Animal, Corpus or Rego (with additional Magnitudes certainly) that causes the wall to heal like a living thing? That was the one that seemed pretty interesting. They even mentioned that Herbam would be preferred so you wouldn't have the image of walls scabbing over first (ick).
In such a situation what might be the timeframe for the walls to heal.
The rule means person for sure. The question in a fantasy game is rather, what it means by person. I expect most magi to consider their familiars as persons. Most troupes will consider 'sentient', intelligent magical, faerie, divine and infernal beings, including 'sentient' magical animals, as persons. These are also the beings, which certainly can make sense of the input from a Magical Sense. Beyond that I see troupe-rule territory - but extremely few will see magic items in general as persons.
The effect Shriek of the Impending Shafts (R:Per, D: Conc, T: Hearing) in Ranulf's Talisman confers the Magical Sense to Ranulf by reason of
It is not an example of an enchanted item with a Magical Sense: this would be anyway obvious nonsense, because Ranulf's Talisman could not act on the Magical Sense of Hearing to dodge arrows, and has no Defense score to increase.
ArM5 p.99 Linked Triggers are very flexible ("triggered by the results of another effect in the same item"). The MoH p.23 Crib with a Mother's Touch, p.24 Guardian of Decency and Soothe the Mother's Anxiety are all good example of such Linked Triggers.
Triggering a repair job around an enchanted stone that was jolted can indeed be done easily this way.