RainOfSteel, do not bring Muto Vim topic here (even if it was the starting point, it's no more the topic ^^; maybe the thread should be split), because I don't want to discuss it here where it doesn't belong.
Seeing MutoVim like do the errata means contradicting oneself. Let's not discuss it here, but rather on the appropriate topic, where, curiously, all my arguments have already been brought, especially about the Wizard's communion.
It is ignored if the heat and flames are magical and Penetrate (if they aren't magical, I can't see how they would Penetrate).
Regrettably, requiring wards to Penetrate renders most of them useless.
You are saying that a spell has to penetrate another spell's magic resistance, but spell have no magic resistance, thus they have not need for penetration...
A spell needs to penetrate its target magic resistance. That's a general rule. And for me, Aegis is not different in that, except that it is a breakthrough and, as such, may be said or not, to follow general rules. Those who think that it has to penetrate will say it does, other will say it doesn't. Since Breakthrough are all about unravelling rules, there is no final answer to that but arguments of the "must penetrate" side render it more interesting to play I think.
Now that we remembered that good principle rule:
A ward target is the thing protected. here, the fire. The fire has no magic resistance, be it magical or mundane.
A vim ward target is the might being. The might of that magical (or divine or other realm as chosen when the ward is either cast or invented (if spontaneous or formulaic, respectively)) being is its magical resistance.
(=> If you go to the "aegis must penetrate" side of the Force, you just apply it to creature outside, and inside (creature being, for inside part, also magi and supernatural abilities user). The other effects affect not people, but spells or magical items.)
But to affect someone (the thing/person) protected with the ward, you will need to penetrate it also.
It's the direct and indirect penetration.
Exar, sometimes, 
What would the ward have to penetrate in this case? A POF doesn't have magic resistance, it's just a bolt of fire. It's established that Magi can't give magic resistance to people or objects except by extending their Parmas, which clearly isn't the case here.
You seem to be reversing the "do wards have to penetrate" argument into "do attacks have to penetrate wards". The answer to that is also no, because these wards aren't a form of magic resistance, they resist physical effects. It would be like saying a piece of rock created by magic can never be lifted by another spell.
That's maybe an even worse example, because Aura of Inconcequence breaks the rules on targeting, uses a made up "special" target level, and in general seems to have been written by someone who didn't understand the core principle that you must sense someone to target them.
That said, wards kind of work that way too, which probably explains why we're all so confused about aspects of them.
There are no target sensing issues here, the Target is the person carrying the effect. You don't need to sense the content of a Room for Target:Room spells.
Aura of Inconsequence is just a Vision/Spectacle Sensory Magic spell, the kind that original research might yield. Don't belittle those who worked on HoH:TL, they could not refer to HoH:MC.
Aura of Inconsequence is an example of what I call Radiating Mind Control. It's not allowed by core rules and if it is allowed it creates all sorts of problems, like the "Ignore the Negative Effects of My Gift" spells we discussed a couple months back on here. There's no suggestion in HoH:TL that it's the result of mastering an inner mystery of an entirely different House after spending years and years on a difficult initiation path. It's just presented as something Quaesitors do.
In any event, my real point was that you shouldn't use a spell which clearly breaks the rules as the example for how the rules work.
I can confirm that since Wizard's Communion is a Muto Vim spell, and this is a topic about Wizard's Communion, a Muto Vim spell, then a discussion of Muto Vim RAW is on topic.
Claiming Aegis of the Hearth must Penetrate utterly contradicts the spell's mechanical description regarding beings with Might. The RAW as presented in the books confirms the contradiction.
I already read that topic. I did mention I had done research about this in my first post. People can house rule in whatever they want or argue with the game creators to change the rules, but until such a change is issued, the RAW are what they are.
You stated:
Where did you get that idea? It isn't found in the Muto Vim guidelines that I read. In fact, it makes it clear that Muto Vim spells are cast at the same time as the spell they are targeting, and even even gives the Concentration roll required to accomplish that if you are casting both spells, and the procedures for casting onto a spell being cast by some one else.
You also stated:
That is not what the RAW states.
The RAW states:
It is quite possible to cast a Muto Vim spell on another spell while it being cast. Procedures for doing exactly this are given.
Rain, if you do not understand that something which is not brought to existence ("cast" for spell) doesn't exist until that moment, then I just can't discuss with you.
Right (to the last part), so it's an even better example than I thought. Look at wards. They use Target: Circle, right? Read Target: Circle, and you'll see that they don't really use it. But instead of writing "special," someone wrote "Circle" and explained how in the case of wards it isn't really "Circle," but rather a special version of it.
If you still don't like this example, how about The Shrouded Glen?
The Shrouded Glen stops them from noticing something, while a ward stops them from moving/acting across something.
The Shrouded Glen is on the original target, guarding the original target. The Shrouded Glen only affects something else if it gets too close to the target, just like a ward.
The Shrouded Glen tries to stop the thing from noticing the target.
The Shrouded Glen is a Rego spell and the target is the thing protected, rather than the thing deterred. Those things (intelligent things) cannot notice the target. Eerily similar. Yet in this case the spell must penetrate, so why not for wards.
Notice all I did was replace "Aura of Inconsequence" with "Shrouded Glen." I may be able to find more examples, too. But I think at this point we have two spells straight out of the books that are very similar to wards, which shows wards are really not dissimilar from all other spells. They may be different from the majority of other spells, but the majority of spells are dissimilar from a majority of spells, so that's nothing special.
Chris
But, remember these two points:
I wasn't using it as an example of the way the rules work. Rather, there was a statement that wards "don't work like 'other spells,' not even a little bit." Yet I have found multiple other spells that wards do work like, not even just a little bit like. Thus the argument that they are so different from all other spells implies they need not penetrate is shown to be false by a single example of a spell wards are similar to that must penetrate. You see, I wasn't using it as an example, but as a counter-example. This difference is incredibly important.
It explicitly breaks the rules in the same way that wards explicitly break the rules. If you don't believe wards could have been written at T: Special, carefully read T: Circle and you'll see they don't fit its description. The writer of Aura of Inconsequence could have written "T: Structure" and made notes about it instead, which is the way the wards do it.
Chris
You do know how to pick the odd spells 
To be honest, The Shrouded Glen doesn't make much sense to me as a Mentem spell. It's a legacy from previous editions isn't it? Enchanting a boundary to look confusing seems more like Imaginem to me. Be that as it may, it's certainly part of the core rules. As a ritual, it's a little less objectionable to me; at least "enchanting the boundary" takes some vis.
Anyway, I don't disagree with you that the effect of wards needs to penetrate. It's the "double counting" issue that bothers me. I think I would also break out the wards which provide purely passive protection against the physical elements and call them "Protection from Fire" instead of "Ward against Fire". These don't require any of the special ward rules and just confuse things.
I'm guessing you have never truly been lost in the woods or out on the water in the fog. Happily, the times it happened to me I had been prepared and so was able to fix things when I knew something had gone wrong. Let me use the lake in the fog one as an example. I could see everything nearby perfectly well, but I couldn't see far-off things. So, since I was going slowly, I could avoid rocks. Also, I know the rocks and the lake so well I can cross it with no danger on a hazy night of a new moon - all I need is the faint outline of the mountains against the sky and I'm fine. But in this case I could only start in the right direction. The whole key to getting lost was that I didn't notice I was veering slightly to the right. I now know better and spend most of my time looking backward to make sure the wake is straight, but I was young and hadn't thought of that. So it wasn't that I couldn't see, but rather that I didn't notice certain things about what I was seeing. This is what happens to people when they're lost in the woods. They usually end up circling without realizing it if they don't know to protect themselves from it. It's not that they can't see the stuff, it's that they don't realize what's happening mentally. So the key to the spell is to subtly divert the trespasser's path. I hope that clears it up.
Try my suggestion above. You may like it.
Yes, I agree there. They also have their own confusion: when do you get 100% protection versus when do you get protection up to only +X? But that's a question for another place.
Chris
It's an interesting idea. What do you think would be appropriate categories for narrower wards? The current wards don't seem broader than other sorts of spells. For example, Demon's Eternal Oblivion affects anything Infernal, as does Ward against Demons. If one is super-broad, then so is the other. For a real super-broad category, consider that ReMe spells affect anything intelligent.
It's not that I disagree that ReMe could cause the sort of confusion that encourages getting lost. It's rather that the description of the spell makes perfect sense in terms of ReIm creating identical landmarks, shifting paths, etc. Also, the Im version would be completely legal while the ReMe breaks the rules, even if Sensory Magic from HoH:MC is used. But that's legacy magic for you.
Cf David Chart's post in the WC errataed errata thread.
Even going with the first errata, this just makes things a little harder, not impossible. It also has an added side benefit: It makes Mercurian Magic all the more worthwhile, since only a group of mercurian can hope to cast a powerful aegis efficiently and without using up too much vis, which fits the setting nicely (even if I prefer the errataed errata)
Claiming wards must penetrate utterly contradicts the spell's mechanical description regarding beings with Might.
But there's worse:
Claiming Pilum of Fire must penetrate utterly contradicts the spell's mechanical description, period (It says it burns the target, and that's all. No mention at all of resistance, right? Thus it doesn't need to penetrate)
Claiming the Shrouded Glen (a D: Year, T: Bound spell) must penetrate utterly contradicts the spell's mechanical description.
Need I continue?
All spells are worded as if they succeeded in penetrating MR, without mentionning this requisite. Arguing that this means a specific spell doesn't need to penetrate is 
That post did not contain any information that suggested Wizard's Communion had any effect on Penetration. It just asserted, "I suppose it could have been clearer." I was asking for RAW, not speculation. The RAW is clear as it stands, Wizard's Communion has no effect on Penetration, which is a completely separate issue from the momentary duration of Wizard's Communion, which you mention next:
That's actually pretty interesting. He's thinking about it. Maybe we'll see an errata update or a 5.1/5.5/6.0 edition of the game in a few years. Or maybe an upcoming book which contains the complete overhaul to Vim. I'll be happy to read about it, and take it into account, when it comes out. For the moment, I'm discussing the RAW. I am capable of making whatever house rules I want, and often do. But I wasn't really interested in house rules in the context of this discussion.
That is an extension of my statement.
I disagree with both of those statements. It is not required that Magic Resistance or Penetration be specifically mentioned in a spell in order for them to function in regard to that spell. This is why I have been admitting this entire topic that the RAW requires Aegis of the Hearth to Penetrate.
However, Aegis of the Hearth has a large section of Might-based mechanics that close upon being useless, are are somewhat comical, if it must Penetrate. Either Aegis of the Hearth should specifically list itself as an exception to Penetration, or the entire Might-based mechanics section should be removed from the spell's description, or perhaps some other solution (I was going to cover proposals in a different topic, and so those would be house rules/suggestions for future editions).
I wasn't arguing that. You're creating a strawman by asserting that I was saying something other than what I was saying.
There isn't any phrase of "brought to existence" in the RAW of Muto Vim.
In my earlier post, I asked you where you got this idea. Your response was that you can't discuss it.
Sometimes you just have to forget who you are speaking to.
So: "MutoVim, guidelines", p159
Otherwise said "it is possible to use MutoVim to affect another spell before it has been cast."
Casting spells, under "formulaic magic" p81:
"If the casting totals equals or exceeds the level of the spell, the spell is cast and the maga suffers no ill effects. If the casting total falls short of the spell level by ten or less, the spell takes effect and the maga loses a Fatigue level. If the casting total falls short of the spell level by more than ten the spell fails to take effect, but the maga still loses a Fatigue level".
Casting spells, under "spontaneous magic" p81:
"spontaneous magic involves the production of effects which do not correspond to a spell the magus knows."
"Before casting the spell, the maga must decide on the effect she is trying to create."
"Glossary" p8:
"spell: an individual use of magic, generally Hermetic magic."
"formulaic magic: spells that have been worked out in detail ahead of time."
"spontaneous magic: Magic created by a magus on the spur of the moment, to meet an immediate need. Generally much weaker than Formulaic Magic, but much more flexible."
Conclusion?
A spell is a single use of magic. It may be formulaic or spontaneous.
When a magus cast a spell, he brings that single use of magic in existence, ie, he does a magical effect.
Reading what I quoted about Muto vim: it is possible to use MutoVim to affect another thing (called incorrectly 'spell'), before even the moment we know if yes or now it will exist (which is the casting).
Hence it is not working on the product 'the spell' during the process 'the casting', because during the process, the spell doesn't exist.
The spell only exist when the casting succeed. If you are saying the opposite (a spell exist before the casting) then you are saying that you cast a spell wether or not you succeeded on the die roll, which contradict the rules.
Otherwise said (all trying to get you convinced):
Spell comes after a successful casting.
If you affect something during the casting, you can't be sure you affected a "spell", since suche spell could not appear if you fail the casting. Thus you are working on something else.
Thus, you are working on magic directly, which is totally correct since spells are individual uses of magic.
Thus, I used the words "magical energy forming the spell"
Which as for consequence that spell is the result of the casting, and MutoVim affect something during the casting, therefore,
Hence: the rules were already more correct thant what the errate introduced, if you read them rightfully in the first place.
Analogy :
you want defecate on the roof of your wardrobe (which has magic resistance) rather than in your toilet. But you only have a spell called "defecate in my toilet". Solution? MutoVim your spell to turn you into a bird.
Defecating is the magical effect; your first range was "touch" (the toilet).
The turning in a bird is the MutoVim; you wanted to increase your range by something like a "Wizard's reach" spell to "voice" for example.
The result is as what you would have done without muto vim, but due to muto vim, you succeeeded at doing it on something which would have been otherwise unreachable.
Muto Vim all the way. Your excrement remain a magical effect, and your turning into bird doesn't need to penetrate any MR of your wardrobe.
No, not so. Are you saying this because it doesn't specify changing the "spell level," and penetration is based of the spell level or essentially that? If you are, please realize you must also conclude that it doesn't affect the casting itself because there is no "target level" to change. Or you could have a similar argument focusing on "spellcasting roll," but it can then be shown that this violates the text in the penetration section. So WC does not work at all? Alternatively it could be argued that it's telling us to change the "target level" of the spellcasting roll, and we have to look up what that "target level" is. We find it is the "spell level." So the "spell level" has been changed for the purposes of spellcasting. But you use that same "spell level" for penetration so penetration is then affected. RAW is ambiguous on this point. I believe they were trying to write things so that dispelling and counter-magic and the like had to deal with an unchanged spell level, so they started talking about "target level" and when to apply it and then things became ambiguous because of other references.
Chris