Another thread leads me to ask this question. Besides consideration of boundary definition and such, do you see anything that would prevent an Aegis of the Hearth from being setup within a sub-section of an existing Aegis of the Hearth, thus creating an Aegis with layers or zones? Now, I'm not arguing for effects that stack. I'm thinking of an either/or effect to restrict access to subzones of an aegis: A creature with might allowed entry in the covenant could operate there, but would be weakened or stopped from entering the subzone, or a magi allowed in the covenant ground would suffer spellcasting penalty when entering, say, the resident paranoid archmagi controlled section of the covenant?
I'd allow an Aegis to be set up inside another, presuming the magus is able to cast it.
I have actually done this very thing a few times.
Even at only level 20, it is sufficient to keep most of the varies minor magical rif-raf in the covenant out. Our covenant has a bunch of might 10-15 hermetic cats, a few ravens with might, and varies others we have gathered up over the century. There are also a few minor magic spirits/ghost/non-corpals.
We have also used it on the Magi level of our Regio (where the Magi live and their important buildings 'Library, Council Chamber, Vault, and Temple of Hermes' are located) during times when we had a bunch of visiting Magi. They were unhampered other areas, but if they managed to get to the sensitive area they were weakened.
A secondary reason to do this this way is to avoid the "seasonal slip" if the outer aegis is renewed at summer solstice and the inner one at winter, then any sneaky entity which crosses in at summer solstice while the aegis is down will have to wait six months to get in through the next layer. Depending on how your sage is handling the variations on sneaking through the aegis.
Boundaries are easy enough to make, lay out some stones or bricks that define a boundary.
This tactic may be particularly useful in sagas where Aegises with +X size magnitudes are allowed. Which would reduce its effective level in the larger area and then cast a higher level ritual to keep more powerful beings out of the area the magi live within.
You could also lay them out like a ven diagram so that to get to the inner sanctum an entity would have to cross multiple aegises, but would otherwise be restricted to a portion of the covenant.
yeah but imagine the vis cost.
Price considerations aside, I think that the question posed in the OP boils down to another question: "Can two identical spells that each target an area overlap in the area which they target?".
I would say a resounding yes. There is absolutely nothing in the rules to suggest that two spells cannot affect the same area, not even if they are identical spells.
I’d probably say yes with caveats. Aegis is fine they would not provide additive protection but merely the highest modifiers would apply except at the edge where the edge or each aegis would apply. Circular wards would also be fine generally but there might be issues around drawing a circle that overlaps with another circle possibly ending the first one cast in the case of Venn diagram-esque circle wards. I can’t think of any off the top of my head but some spells might imply a more additive way of going about things that might seem to break certain rules
I think ven wards would depend on 1) how the circles were drawn and 2) what they protect against. For example if you have a circle drawn with a brass ring that intersects a circle drawn with Lapis lazuli then as long as there is lapis Lazuli at the intersection points on the bronze circle then the drawing of the two circles would not interrupt each other. Obviously if one ward if for corpus it must be drawn second, and if the two wards are for the same art then likely the second would break the first if they are based on duration ring. Using a different duration (like moon or year) would also prevent breakage.
I am sure I am not alone in having overlapping wards come up in play. Having smaller wards within a larger ward or AotH seems like something that would occur fairly often.
Intersecting wards are more difficult and would highly depend on the design and materials used. I agree that a venn diagram design could be done in which the individual circles would not be broken. You could for example have each material at half thickness where they pass over each other.
Y’all are getting all complex. I’m just here drawing wards in chalk.
Chalk is fine for a ward you need "now", but why would you not use a more robust material if you actually have the time and capabilities to?
With a spont spell you can form a circle that is made of something like stone fairly quickly. Muto, Rego, heck even Perdo could do it (though the PeTe spont would most likely be level 10 or 15). Actually that would make an interesting little spell, I think I might write it up.
Duration diameter, range touch (you don't want concentration since you will be casting the circle that you are drawing...)
Yep. It would be a judgment call on T: Part or not and base 2 or 3 (if Weaken would be enough to leave a usable mark). Rego and Muto would be easier, but a Perdo specialist could do it.
I think it would have to be target:part because otherwise you are destroying the whole of what you want to mark. If you want anything resembling a neat line it will probably have a re requisit.
I was leaning the same way on target: part, which is why I came up with the level 10 or 15. You are looking at Touch (+1), Diameter (+1), Part (+1), Stone (+1) so if Base 2 is enough then 10, but I am leaning more towards it not and so you need Base 3.
Though an interesting variation is to use a ring duration where the ring is created via temporary magic (non ritual creo, perdo that destroys a property like redness) so that if the circle hasn't been triggered to drop before that point it will fall when the duration is up.