Unraveling the Aegis

Ah now I see what you mean. It seemed like you were advocating something else, sorry.

You would need to reivent the whole darn thing.

A houserule: any attempt to dispell an Aegis must penetrate the aegis even if the caster is inside of the area protected by it because you are casting at the spell itself rather than just at the protected area might be less of a pain.

Using this house rule you won't have the ritual vs. non-ritual magic unraveling spells and, in your above example the caster would need a casting total of 20 for the spell + 20 for the effect of the aegis + 40 for penetrating the protection of the aegis = 80. That seems about right to me. The dispelling magus could do it from outside of the aegis for a total of 60. Also remeber that the dispellig magus must be either able to sense the spell or have an AC to it (such as one of the medalions) or else they run afoul of the law of Arcane connections. (I suppose that they could develop a spell with a target the same size as the Aeigis instead but I'd wager that this would make things a great deal harder).

Paris and the other:

We encountered the same problem as Paris' troupe did.
It cause problem for the utility of autonomous defencives spells among other rituals.
Think not only of the Aegis, but of many other rituals: Watching wards, Shrouded Glen, etc.

Demanding a ritual to dispel another ritual spell solved that problem in our campaign.
Tyrel idea would probably be OK, but only for the Aegis. Other rituals may be a waste of Vis.

Would a simple, few second spell "unravell" the work of hours of casting and spending of Vis ?

Not only spells of level greater than 50 are ritual:
ArM 5 : p. 115: " Certain powerfull spells and spells inherited from the cult of Mercury are also Ritual Spells."

We interpret this as "any spell that feel like it ought to be a ritual, is a ritual."

It's a small step from there to think that a spell that can dispel a "powerfull spell", need also be a powerfull spell. This explain easily the need for a ritual to dispel a ritual.

We found this interpretation of the rule very intuitive.

Not quite sure why you think it is too easy to dispel an aegis (or any other ritual). To use the unravelling of vim on it, you would have to be a hermetic magus, and that means dispelling such rites would have you slapped with a tribunal case for forcing the magi depending on the ritual to waste resources re-casting it.

Non-hermetics fall outside the rules in any event, but would non be familiar enough with an aegis to dispell it in this way.

Further - you are saying that if a ritual goes awery, there shouldn't be a way to counter it? And that rituals are as strong as enchanted items! (Or should we remove the disenchant spell, and let that become a lab project?)

Unraveling your own spells is easier, though it is still a problem with the whole requiring a ritual. (could ceremonial casting bring a sollution?)

We had a hermetic / hedge wizard in our covenant, who wasn't really afraid of the Order. (that is, we had some quesitors look into it, but they are not around all the time) He could have disrupted the Aegis, but he was (we finally killed him) more of a mentem and imaginem person.

Besides that, most magic, demon and fairy 'magic' also follows hermetic rules somewhat (modded by the SG usually), reason enough to fear for your costly rituals.

I might have missed something big here, but how is unravelling your own spells easier? That is unless you have harnessed magic (or similar)...

You need to know a little of the magic you're up against to use the unravelling spell - so anyone without a magic theory score will need a more general effect...

Oh, and as with all magic, you must be able to sense your target, so you must first detect the spell... (Maybe an idea to mask your rituals instead?)

Well, I don't say that everyone should have the same experience as we have. I just say that it was our experience : take it or leave it. Let's not underestimate the way each of us play Ars Mag : this has a major impact on how we use/interpret the rules.

I'm not sure I understand correctly.
As in any spell, a disturbed ritual spell would probably be not be fufilled. It depends on the circumstances of the disturbing.

I said ritual spell need ritual to be dispelled. As you say, it means that both enchanted items and rituals need rituals to be dispelled. I didn't wanted to advocate that both are of the same strenght, (nor would I need to do it to support my previous claim ?)
The disenchent spell is good as it is IMO. A spontaneous PeTe level 10 spell can destroy most enchanted object...

I don't see it.

The rules say that most power should be expressed with an hermetic spell, but I think that was meant to be a shortcut for the rules. In character, in Mythic Europe, the Demon, faiery, etc have powers very different from hermetic magic. It's just that you convert that healing power from a Faery to a CrCo20 for simplicity sake. I don't it was meant to say that it was a similar power in any way.

At the same time, it also means that the requirement of knowing the fabric of a spell to be able to dispel it is an hermetic requirement. So a demon could have the power to dispel any magic, even that he doesn't know of, if the SG design it like that.

Hiding the Aegis is a real good idea, haven't thought of that...