Thanks for the last couple of responses!
I still haven't completely decided upon the final details on house ruling the wards - but as such things goes in rpg-sessions the magus who had earlier cast personal anti-animal wards on everybody didn't remember to renew them after the sunset... so the wards were never tested against the designated enemies...
Unfortunately, an adventure isn't "most of the time." Make it day, personal, individual. Make a few items. Voila--major virtues. Besides, circles are cool, so make people use them.
Now, that's another problem than that you mentioned before.
So we know the wards as written are ... suboptimal, and we should use houserules to fix them.
If you want to avoid items with (R:Per, D:Sun, T:Ind) Wards, a good way to do that is to give Wards some decent base level and require them to penetrate. Then, unless your players' characters create one shot items, the penetration of their items will be that low that they can only ward off beings they can beat anyway.
Soon your warder will notice that, and revert to casting his personal Wards every morning and evening, after renewing his Parma.
Assume that the SG is easy enough on him so that he always can guess when an adventure is around the corner. Then my trick is to have enough different Ward spells, one e. g. warding against Water Faerie bodies (ReAq), one against the powers of Magical creatures (ReVi), and so on. To be protected against most supernatural beings that could come his way, our warder then needs some 30 or so spells. And the first time he wakes up or beds down in an unaligned Aura, or under uncomfortable circumstances, all his spellcasting rolls will be stress - so a botch is quite likely.
So your warder would have to master some 30 spells to counter that ... and still beings of sufficient might can affect him ...
IME lots of spells bestow effects mirroring major Virtues. Just consider Shapeshifter or Entrancement. So that argument doesn't really mean much to me.
Kind regards,
Berengar
You've said that bit about strictly applying warp rules several times--of course we do. The bigger change for our storytelling isn't very hard to do--warding against mundane creatures or against humans or iron or wood. These are low magnitude spells that don't need to penetrate mundanes. However, these effects have profound ramifications for our stories and our drama. Low magnitude, non-constant (i.e. "day" effects for a week or two a year) effects never cause warping, and high magnitude, personalized, non-constant ones don't either. It's very easy to utilize these just on an adventure, not while in the lab.
On a further sideline, tailoring an existing effect to a specific person sounds exactly like a MuVi "superficial change," akin to changing a sigil, and also relatively easy to pull off, and that would also circumvent your suggestion to wards.
We could artificially bost the level, sure, but I find the whole scenario unappealing. I like a low fantasy feel--where ambushes are scary and a hidden dagger is too. Just make it a lesser limit imo, wards must be cast via circle--a flaw in Hermetic theory. It can get very exciting to get one up then. I like that drama in that scenario, and I don't like the other more passive defense. It comes down to what's fun, and your changes are less fun for me.
Best,
-m
You know of course that you don't need Wards to do that. IME here the important thing is still to require enough different - form related - effects to guard the magus against mundane threats.
Provided you don't have to cast them by the dozen in unaligned Auras - but I said that before.
If an SG allows players to bamboozle him into that, his campaign is really in for a few problems. But ArM5 requires a special version of the effect to be invented, not just made up on the fly by MuVi.
Kind regards,
Berengar
Personal wards are easiest and most certain way to go about it. Other defenses have larger flaws. On requiring dozens of mundane wards--am I suddenly having assassins come out of the woodwork with silver knives and bone arrows? I feel that's a contrivance that degrades the setting for little positive payoff.
IMC there aren't dozens of unaligned auras in regular adventuring, and most of them are escapeable, like the Divine Aura in towns--just leave town to cast spells. If vast auras in settings where players are forced to cast in them routinly are the norm, I am again contriving the setting to get around an effect in the same way that I would be contriving enemies to have bronze or gold weapons to get around these simple personal wards. I don't like that choice, and I don't understand how it benefits the game directly or indirectly as an interesting choice.
Are you suggesting that's an unreasonable interpretation of the rules? I can't think of very many applications of that general guideline at all, thus I'm inclined to allow it. Certainly there would be some MuVi effect that would make it possible--it's not like it's a lesser limit or something. Further, the effect could be invested in an item with the ability to ward, and could alter it's own effects with metamagic.
See, your vision bends lots of rules, alter the level of base effects if they're personal, calls for me to add contrivances to my setting, and so on. I like simpler, and I like drama--I just don't like your edit.
Obviously it works for you, however. Perhaps you can tell me a time when your version was interesting? For example, when we made a Dante-esque journey through the first several circles of Hell, we had some very dramatic scenes where we needed to put up a ward in time. Having wizards draw circles regularly when they go to bed on the road adds to the ambiance of our games. How does your version of the rules add to your game--that's the most important question to me.
Best,
-m
Something to remember about mundane wards - they tend to do too good a job. A ward against wood would prevent you from using any wooden items, like a mug or a staff, and a ward against silver would prevent you from accepting money...
Another thing to remember is that someone who seems immune to cold steel is going to get an reputation to that effect - and so any assassin would be equiped to deal with the problem...
For most groups I know, this really isn't much of a problem, as people usually don't really want to have their magus killed... Thus it is not the goal of the storyteller to kill the magi. Deadly danger is the realm of the grogs, and most of them lack the access to wards every day...
I'm not sure about that. How often will it come up, and how long before the reputation forms? Okay, if you are often stabbed with a steel dagger, people will learn unless you go to some effort to conceal your protection, but most magi won't be attacked often enough to form a reputation, particularly not as they will often remove the perpetrator with extreme prejudice - there may well not be any witnesses.
If a magus were worried about that, though, he could simply spread the rumour that he's immune to all harm, rather than just steel. Who's going to say "After he killed Bob, the wizard laughed and said he was protected against weapons. But I recon that's not right; it'll just be the steel Bob was using, right? I'll just dig out a bronze blade..."
Ulf beat me to explaining the biggest weakness of using Wards to protect against plain mundane threats: that they ward off many, many things a magus needs to get in contact with during the day: drinks, food, hands to shake, the magus' staff or atame dagger, flowers to collect, and even the carcass to collect Vis from with ReVi 15 Gather the Essence of the Beast.
IME and IMCs the most important protection spells against mundane threats have been the following:
(1) InHe 15 Shriek of the Impending Shafts - and especially its R:Touch InHe 20 version, so as to also protect familiars. There's just too much paranoia about outraged peasants, offended faeries, dutiful guardsmen and even disgruntled grogs taking a shot at a magus' back with bow or crossbow. 
(2) The InTe versions of this spell, helping to avoid thrown boulders.
(3) ReIg 25 Ward against Heat and Flame. Not really a Ward, despite its name, but protecting far better against secondary effects of the fire.
(4) PeIm 20 Veil of Invisibility. They can't see you - so they won't hit you and concentrate on your grog instead. 
It makes a lot of sense to augment the spell to also hide the target's smell.
(5) ReMe 25 Aura of Inconsequence. Avoids mundanes' attention to the rare magus who can behave himself.
Indeed. But it's not my contrivance.
Ahem - I fear that this time the ArM5 authors 'contrived'.
Look it up in the Divine, p. 11f: wayside chapels, crossway crosses, the little altar underneath the tree with the clay statue of the Madonna, and the fields, mills, barns of believers are all Dominion. So your magus might have a few miles to walk out of town before he is out of an Aura he's not aligned with.
Look it up in GotF, p. 30ff: Rhine Tribunal faerie forests are vast affairs. If your magi wish to explore their depths, they will have to refresh their protection spells within, if they are not D:Moon or higher.
I don't see why you object to this. You can always houserule differently, of course - just do not assume that I know before you tell me.
Definitely. It will cause you lots of problems in a campaign running longer than a few years, and it goes also clearly against the written rules of ArM5 p.168: "Designing an effect for a particular target requires, in Hermetic terms, that a special version of a Formulaic spell be invented." Why houserule yourself a headache?
Kind regards,
Berengar
I still don't understand how your version is more interesting or more dramatic. 
The Re spells aren't so bad to dispel for a mindful magus, and I find the argument that they create problems, well, superficial. It's not so hard to get around their problems on an adventure.
Your suggested alternatives... are interesting substitutes. I like many of the spells that you list actually, as they require activity and risk, compared the very passive Re spells. They do not make the magus or friends immune, just aid in avoiding. My alteration encourages their use by denying the more "brainless" alternatives, and I like that too. I've seen wizards killed in Veil of Invisibility, and I've had a character of my own seriously wounded and even incapacitated on several occasions while invisible, even as he could move in utter silence at the same time. This is good.
However, personal ward spells are simply better in every way, rendering the magus--or a friend--utterly immune (interestingly you cite what is actually a ward with a slight twist as an alternative to wards--it really is a ward). The level difference isn't so profound--5 for animals, 25 for humans, plants, or steel for a day. 20 for diameter personal effects that would have triggers. Any effect could be extended in duration or range or both and keep its magnitude below 30 with MuVi effects (with all effects in an item, or by spell).
In my experience, the novelty of being immune to an army wears out pretty quickly. It took us one story to realize as a group, "wow, this is really dumb." Is your setting is full of demons and dragons and mundane threats, or all your wizards are 60+ years out of apprenticeship, therefore requiring a different power level? Or are you generally a player?
They'll walk it. Or 7LStride it etc. Or sleep outside of town. Wouldn't you?
Now, also remember this doesn't only impede abusive spells, but also interesting spells, so it creates other problems too Usually 1-4 wards are all a person needs. Also, the general threats in that vein would be faeries I imagine. Maybe some mundanes here and there, but in a faerie forest, usually there's a story centered on faeries.
I think it's the rules as written p 168 doesn't account for MuVi spells any more than the section on sigils does. As I said, it's not there's a lesser limit here. If a formulaic spell can change a sigil, the form, the technique, then it can change more subtle elements as well. At the worst, the metamagic spell has to be tailored to an individual--similar to how certain metamagic spells need to be tailored to a specific form (Unravelling the Fabric of...). This MuVi effect really only affects high powered, occasional effects as no one uses constant effects much anyways with the warping risk.
But if that one aspect of things is super intrinisc to your balance, then yeah, you'd have too step in in the same way you'd have to step in if any spell unbalanced your game. What other common use, shareable effects are as problematic as personal wards? Why contrive the whole setting around them, rather than just dominish them? Im still looking for the payoff--thus my very serious question, why are these personal wards "more cool" than circles?
I think your houserules are a headache 
My version has one rules edit, and it seems to me like you have a lot!
I think these personal wards are the equivalent of the Level 5 Inivisibility oversight in other editions (4th wasn't it?)
Then tell us how. IMCs over 20 years nobody ever used T:Ind standard Wards to ward off mundane threats, exactly for the problems they create for the daily interaction with the world around.
Mine had a lot of problems while invisible as well ..
With the ReIg spell you can see the real difference between the standard T:Ind ReIg Ward keeping fire or hot things away from the target, and a protective spell designed for a specific purpose, like 'Ward against Heat and Flames'. The standard T:Ind ReIg Wards are utterly useless in a burning forest or within a house ablaze, as they either keep the hot air out and suffocate its target in a minute or two, or let it through and kill the target in a few seconds by burning its lungs.
No. Sleeping every day outside of town will cause the magi to be suspect after the first few nights. 'Seven League Stride' out of town can cause quite some suspicion as well, as there is not only Dominion but also lots of people around. And locking yourself up in a room of an inn every evening would be highly unusual, rarely possible, and certainly cause similar suspicion even faster.
I find that interesting, and by no means problematic. (Ok, the old Chinese used 'may you live in interesting times' as a curse ... but most PCs appear to think differently.)
That would depend on your houserules, I reckon.
It is very clearly excluding them.
If the caster just knew how to change them. That's why the rules require the research of a Formulaic spell.
Kind regards,
Berengar
I am currious MarioCerame, how often does your magi fight mundane armies?
For my group, the magi being immune to mundane weapons would simply be a lead to a new set of stories - After all, it has never been a point to kill of our favorite characters (the magi). Some problems that would tend to arrise from such immunity are: Demonic tempation to the sin of pride. Holy enemies praying from help from the Lord, and getting a miracle... Non-mundane problems (which seems to be the most common background for stories in any event).
I'm glad to see that the ball is still running on my initial question - I haven't anything to add for a while, but I've been taking in all your arguments along the way.
I'm still undecided on my final take on interpreting/house ruling wards, but a few preferences I have decided on:
I want to include magic resistance/penetration - bc it streamlines Ars and because it opens up for potential stories and role playing looking for things/ways to augment your penetration in a coming confrontation. Stories are after all the core of Ars,
I want to make Individual wards weaker than Ring/Circle wards to encourage the use of Circles - again bc it is my sentiment that the circles makes for more interesting themes than making them more less absolete in regards to wards,
they at least ward against the physical thing warded and they ward against the mythical powers of the creature - but the jury is still out on whether to ward thrown or missile weapons and long enough wielded weapons (there are plenty of argument for including this, but I haven't decides as this might be the area for making a difference between Ind and Circle wards.).
And a small sidenote - I don't think that the prefered solution for me and my troupe is warping. I don't think it would make a big difference in what our magi might chose to do and even if we made it heavily warping it would just mean the surmise of the magi to final twillight earlier than otherwise. On the other hand I agrre that to personalise a spell to avoid warping you have to invent it that way and can't simply solve the issue with MuVi. This is not only because of powerlevel but simply because I think to do it otherwise robs you of obvious story potential.
Thank you for all your inputs and ongoing discussions! I'll surely keep following it to get futher inspired by it.
Cheers!