Trying to mechanize "cannot scry" from Limit of Time, using the last column on p58 of TMRE. I would say "rolling a dice" is a pretty good match, although having 10% or less of failing might be considered "should succeed" for Divination purpose.
Just to add some fuel to the "suppressibility of the Longevity Ritual" side of the discussion, I'd point to RoP:F, p.129, the first of the Ware guidelines:
In looking at the guidelines list, we've also got the following under Perdo Vim (emphasis added):
Which seems to be a generalized version of Disenchant, in the PeVi section of the main book. So this tells us that a Longevity Ritual is considered to be a type of enchantment. OK. I fully agree that DISENCHANTING an enchantment is a ritual. However, In looking at the Rego Vim section, I'm not seeing any requirement that SUPRESSING an Enchantment is a ritual. We do see examples of how to suppress a Ritual (again - Guttering of the Hearthfires), which is considered to simply be a normal spell. I'll look a bit more, but I'm not finding anything (again, serf's parma) - but that tentatively tells me that either
- It is impossible to suppress an enchanted item, or
- Suppressing an enchantment is a normal magical effect.
Of those two options, #2 seems more reasonable.
To explicitly state my reasoning:
- An enchantment creates a magical effect.
- Magical effects can be suppressed using formulaic Rego Vim, as long as they can be reasonably identified.
- A Longevity Ritual is considered a Creo Corpus Enchantment.
- Therefore, a formulaic Rego Vim effect can suppress the magical effect of a Longevity Ritual.
My advice is to be really careful with this. If ReVi can suppress a Longevity Ritual this easily, then a foreign Aegis of the Hearth should as well.
That was my initial thought as well. It also came up in my research for looking for justifications for suppression not causing warp - but then the long-term warping rules specifically call out wards as causing warp for individuals inside them (even if they're not part of the Form of the ward), with Aegis and Parma being the explicit exceptions. Hence my focus on individual spell targets for suppression, rather than targeting the individual human being. But then I realized:
- You need to suppress a LR for half a year in order to keep it from granting its bonus (as described in RoP:F, above), and
- How often does that actually occur?
My main thought was "only if you're in someone else's Covenant without being given a Token for 3 seasons - probably if you're copying a text, or something like that." Other than that...I couldn't think of anything (other than being held captive) that would qualify.
It's amazing the kinds of problems that pop up with Aegis of the Hearth. What about Familiar Bonds? I hope if 6th edition ever shows that Magic Resistance in general operates in a consistent fashion (easiest solution is probably to make all spells Aimed and give everything with MR a bonus to defense).
I believe it's been established that Familiars count as magical creatures, so unless they are given Tokens, they are affected by the wards like anyone else. (ie, they can't enter unless their MM is higher than the Aegis, etc.)
I would imagine that the Familiar bond is considered to be an enchantment with a magnitude of whatever the total the magi used to create it. If it's not high enough...it gest surpressed.
However, I seem to recall that there was an exception for effects that were already running - ie, if it's already been cast, Aegis doesn't affect it. If that were the case, then Familiar bonds and LR's are safe.
Of course, I could also be smoking crack on that.
Hmm, I remember something about losing (or not) invisibility when entering the Aegis, but not where the discussion ended.
Well, just looked up the Aegis, in the book (AM, pg 161). Looks like Aegis specifically DOES surpress effects that are cast outside it, but brought inside:
As to whether it affects a LR or a Familiar Bond? Doesn't specifically say. However - they are magical effects, and they are defined as Enchantments. So I would argue yes. However, the RAW text only calls out "enchanted devices" - which in AM5th specifically refers to only Talismans, Enchanted devices, lesser enchanted devices, and one-shot items.
As such, I think that while the case can pretty strongly be made that both LR's and Familiar bonds are affected by a hostile Aegis, it's not specifically mentioned in RAW.
However, I'd still argue that they're affected. The consequences of that, however, don't seem to be very important, as it's only affected by the "1/2 the level of the Aegis" aura effect. And what's the minimum level of a LR? I'm guessing at least 25 for most magi, if not 30. So they'd have to be hanging around in a hostile lvl 50 Aegis for 2 seasons a year for it to be an issue. Similar with the Familiar Bond - it would be suppressed at 1/2 value, so the magi would have to have a bond of similar weakness (25 or so) in order for it to affect them.
However, neither a LR nor a familiar bond has penetration - so it may very well be that their penetration is (0), at which case it's automatically suppressed. If that were the case...I can certainly see an issue with not spending a lot of time in a hostile Aegis - but mainly for the familiar aspect: if I had one, I wouldn't want to be cut off from it. In contrast, the (lack of) issue regarding the LR still stands: unless you plan on being there for a good portion of the year, it's a trivial disadvantage.
Careful, you've included a really big assumption that hasn't been written into the rules. Consider a being with Magic Might inside the Aegis of the Hearth. It tries to use a R: Personal power with 0 penetration on itself. The effect is resisted, yes. However, that means the penetration is reduced. This means... it still works because there is no resistance. (Negative penetration is OK if it doesn't need to beat Magic Resistance.)
The issue is that it doesn't say how items are resisted, just that they're resisted. Meanwhile there are different ways of dealing with resistance (spells vs. powers). See here for more information: https://forum.atlas-games.com/t/a-guide-to-aegis-of-the-hearth/6092/1
This is why I only warned caution. Aegis of the Hearth is not necessarily an issue alongside ReVi suppression. It depends on how you play the Aegis.
The way I would rule it is that circumstances change.
If the Divination suggested that no debilitation would occur for the year, and the magus then suppressed the LR, I'd rule that cirumstances changed dramatically when I "surprised" the player with a reroll without benefit of the LR.
Similarly for the opposite.
This isn't really screwing the player; using divination to avoid destiny never works out well.