Hi,
Ah, yes. I forgot about that one. I'd keep summae, but writing one that's even a little bit better than the current Authority on a topic would require a significant breakthrough. I imagine that the state of the Art right now is a 17 chapter volume, lvl 5 Q 15 in each Art, lvl 3 Q15 in Magic Theory and lvl 2 Q15 in Parma, written by Bonisagus, called "Ars Magica...."
Anyway,
Ken
You cannot go from Target: Individual to Target:Group with FFM because that is a two step (+2 mags) jump. FFM only allows modification of up to 5 levels (+/- 1 step) to a spell. You could go from Part to Group, however, as mention above.
Hi,
I think you reversed SirG and I....
Note that my version of Secondary Insight is a minor, general virtue that would have much less impact on apprenticeship because it does not apply to studying from a book or teacher. It's good for an adventurer or lab rat, and also useful for a companion.
As for my latest version of Diedne, it's still not all that wonderful, because I went and crippled Formulaic Magic. A starting Diedne can already cast spontaneous magic with flair, but is severely behind the power curve, even if he is optimized:
Diedne Magic (Ken's)
Puissant Magic Theory
Affinity with Magic Theory
Cautious with Magic Theory
Then 93xp in MT yields Magic Theory (spontaneous magic) 7+2. Adding a stamina of 2 allows this fellow to spont any level 11 spell, without fatigue or botch, not including auras and casting penalties or bonuses. 90xp more provides a 9 in one Technique and one Form, allowing level 20 sponts in a TeFo and level 15s in the broader Technique or Form only. This is solid, really good, but comes at the expense of real power: The best Formulaic spells are hard for this guy to learn or cast. My only real problem here is that some lab rates, especially Verditius magi, might like the synergy with magic theory too much.
I mostly like it, but think I'll have another go.
Major Hermetic Virtue: Diedne Magic
Your lineage is more closely tied to House Diedne than that of other magi. You do not necessarily have a Dark Secret or bad Reputation. You do suffer from the flaws Poor Formulaic Magic, Weak Enchanter and Loose Magic. You gain no points for any of this. You also suffer a -5 penalty to study totals when you learn or invent a formulaic (but non-ritual) spell, including during character creation. Finally, you do not learn any spells during your apprenticeship. However, when you cast spontaneous or ceremonial magic, your Casting Total is equal to your Magic Theory plus half of your Casting Score. This costs no fatigue and never botches. You have the option to spend a Fatigue and add a stress die to your casting total, but risk botching. For every point you have in Magic Theory, you may choose one spell Mastery special ability other than Magic Resistance to apply to all your spontaneous and ceremonial magic.
Ok. This is closer to what I have in mind. The Diedne Magus' use of magic is distinctive, characterized by lots of flawless, low level spells with decent penetration and great casting options. He's not very good at Formulaic Magic, is really bad making enchanted items, but might have a fine familiar and longevity ritual. He's powerful, flavorful, and ultimately limited compared to a magus who has specialized a little.
Anyway,
Ken
(oops! 
Fixed that, thnx!)
Nope, not in the Virtue. Nothing about Ind/Grp, only +/- 1 magnitude to R/T/D & etc. And, as has been mentioned now by more than me, that's +2 Magnitudes.
And I agree with you re many of the examples, btw, even if that's not the way I would have phrased it. The examples were often taken from earlier editions, and they made more sense with those rules.
Shiver of the Lycanthrope - Range = Touch. Sign me up. 
Oh I forgot the part target! Thanks
Then my character can decrease the size of a group when using his FFM based on the Arm of the Infant spell. 
OR
I can make invisible only the heads of people. Or make it visible 1 pace away from their body using wizards sidestep. 
Its a funny virtue.
Ulf: what other things are strong in your game? Cause Scent of Slumber and DEO (lvl. 10) are by far the most powerfull spells in our game too. That's why we've restricted them a bit:
Scent of Slumber -> when momentarily changing the state to sleeping, the subject will fall to the ground, and wake up again because of that. (using versions of the spell that have a longer duration, but where the subject is still awoken by noise damage etc. this also happens)
Demons Eternal Oblivion -> we've got somebody who mastered this spell (for 4 copies per casting) and simply slays any demon she lays eyes on. Therefore we ruled that casting this on non-demons gives them warping points (and the spell has quite a demonic show of black lightning).
Some of our house rules 
I guess that ruling a regio boundary as an undefined distance is also a house rule. In practice this means that you cannot teleport over regio boundaries with 7-league stride, but you can with leap of homecoming.
Paris:
You've really made the scent/call to slumber category of spell useless, haven't you? I just started having magi learn the spell, and master it for magic resistance.
As for the DEO, never let the players know if it is working or not... So, you could be encountering a powerful demon, or it could be non-infernal. As for mastery, that is abit tricky - since you can't practice it without having a demon to cast on...
We've ruled that regios are not really part of this world, so even leap of homecomming will not work. You need to enter in the normal manner...
No, he hasn't, he's simply disallowed cheese spells to do things that don't follow the RAW. And doesn't let wishful thinking overrule the guidelines, and the effect as defined.
If someone is lying down, comfortable and warm, with nothing on their minds to worry them, and they fall asleep, they might sleep a long time- or not, depending how tired they are, how comfortable they are, distractions and interruptions, etc etc. This is "momentary" duration - the magic starts the process, then it continues naturally, the magic is done. Paris has ruled, reasonably, that if someone is standing up and falls asleep (I've seen it), they fall, but they awake when they hit the ground (Funny, but that's gotta hurt!).
(A SG could rule that the "momentary" duration lasts long enough for them to hit the ground and get settled, certainly, but nothing states that is how it has to work. At best, the mage then has opponents sleeping a natural sleep, when their bodies/minds quite possibly have no need of sleep, and the slightest noise, breeze, or uncomfortable surface will wake them up in a breath or three, as is natural for sleep.)
If given a duration of Diameter or Sun (or longer - Cinderella, anyone?), the spell keeps them asleep magically, and no amount of slapping, cold water, marching bands or falling off a horse will wake them up. Set their boots on fire, and maybe...
Do you allow other momentary effects (other than Perdo) to continue with magical force behind them? The Rego forces the target's mind to a different mental state (asleep), but then nothing "forces" it to stay there.
Unfortunately, there are many, many spells in the RAW that are not clearly as effective as one might at first hope, or believe. And, many of us (myself included, certainly) discovered Ars while we were saturated with pre-conceptions from other RPG's, of how a certain spell effect should work - this, too, causes us to "read into" spell descriptions elements that just aren't there. This has been discussed elsewhere, and in various language, but the fact exists. SG's and Players alike should be on the lookout for same, to avoid the sort of "I'm being cheated" reaction Ulf might now be experiencing.
I've been using the following house rule for about a 2 years now, and it seems to be working just fine.
The first time a character casts a spell during each game session, the character gains a point of mastery experience in that spell. This is gained (once) for every different spell used that session.
We only play about once every 3 weeks (if we're lucky), and it seems to be perfectly in balance. It gives the players something fun to tally at the end of the night, but hasn't get out of control, or seem to unbalance things. Mind you, I don't have any players casting spells just to get the points (and if it was the case, I'd overrule it anyway).
eric
I think I'll adopt that. Except that longer-duration spells ought to keep the subject asleep, no?
This is a general problem with combat spells, not just with DEO. Not sure how to deal with that, but then perhaps it will be less of a problem in my upcoming game for other reasons.
I've more or less finalizied my list of house rules, for the time-being, and it is here; a few highlights:
Weaker Focus
A magical focus provides a bonus equal to half the score of the lowest Art, round down. [This makes Magic Focus a useful virtue, not a must-have.]
Faerie Magic
Replace the spell parameters allowed through Faerie Magic with the following list:
Bargain (Special): As per core ArM.
Days (Duration): The spell lasts a set number of days and nights, determined at the spell's design, not exceeding 33. Each day or night is a Sun duration, and if it cannot apply the spell ends For example, a spell designed to last "a night" will falter immediately if cast at daytime. This duration is equivalent to the Sun duration for the purposes of spell design.
Weeks (Duration): The spell lasts a set number of weeks, determined at the spell's design, not exceeding 16. Each week lasts precisely seven days from the time of casting, ending at sunset. Casting a spell with a Weeks duration requires raw vis like a Ritual spell (but not that the spell be a Ritual). This duration is equivalent to the Moon duration for the purposes of spell design.
Year+1 (Duration): As per core ArM.
Bloodline (Target): As per core ArM.
In addition, characters with Faerie Magic may develop the Faerie Magic ability, create faerie charms, and bind faerie familiars - see Mystery Cults for details. Unlike what Houses of Hermes: Mystery Cults says, faerie familiars do not resent their binding.
Familiar Assistance
Familiars don't count towards the maximum number of assistants you're allowed in the lab. So, for example, a magus with no Leadership score might enjoy the assistance of his familiar and his apprentice at the same season.
Circles & Rings
A circle needs to be drawn for effect when using the Circle target or Ring duration. The circle is broken if it is actually physically broken, which may be more or less difficult depending on the material - a metal ring won't be easy to break. Even a small break such as a hairline fracture or smudge is enough to break the circle.
However, a Circle target needs to be exposed to be effective. If enough of the circle is covered up, the circle is still active but won't affect things beyond what's covering it. For example, if you cover a metal ring in a thin layer of dirt the ring might affect the dirt but not whoever is standing on top of it. Small disturbances, such as a leaf falling over a circle's line, can be ignored as long as the overall shape remains clear and evident.
A circle may be moved. Thus, you may for example imprison a ghost in a round mirror.
Spells of non-Momentary duration with a Circle target may apply the spell effect to either (a) all the targets present in the Circle at the time of casting who haven't left the Circle, or (b) to any target currently within the Circle. The spell can only be designed to do one of these things, not both. If the first option is used, the spell stops affecting any target that leaves the Circle and doesn't reapply if it returns. Thus, a Circle of invisibility with duration Sun may either grant invisibility for a day to a group of people waiting within it, or serve as a location where anyone that enters is rendered invisibile.
The Ring duration ends when the target moves out of it or when the ring is broken, whichever happens first. Accordingly, the target of the spell must always be contained within the ring as the spell is being cast. (Created things must be created within the ring, and the spell fails should they leave it.)
Wards
Wards do not need to surpass the creature's Magic Resistance to ward against it. They ward against creatures of Might as per the guidelines, regardless of the creature's magic resistance.
[This allows magi to ward themselves against creatures relatively easily. Actually affecting the creature may prove more difficult.]
Automatic Area Lore
In addition to any normal XP gain, you gain 2 XP each season in (Area) Lore, typically Covenant Lore. This stops once you reach a score of 2 (15 XP).
You may always assign Exposure XP to (Area) Lore.
Wounds & Study
A wound penalty of -3 to -5 endured for a month or more reduces your advancement totals to 2/3 [not 1/2, as per ArM5 p. 179], as if you've been distracted for a month (ArM5 p. 165).
Extended Book Rules
...
In addition, books may be written using resonant materials. This provides a +1 bonus to the source quality. Any book, on any topic, may incorporate resonant materials [unlike what Covenants says]. For example, a book on Area Lore may be written on materials incorporating the area's scents. Crafting a book using resonant materials is often difficult or expensive, however, and typically requires the use of minor magics. [Further resonance as per Covenants is not possible, neither is clarification.]
...
A book may be copied quickly, for a x3 increase in copying speed. This denies the increase to craftsmanship through superior scribing or illumination, and furthermore imposes a -1 penalty to the quality. [This combines the core rule and craftsmanship.]
There are a number of changes to book rules in this saga, and this is a good place to note them.
A summa's level may be lowered to increase quality, but the bonus is limited to +(Com +3) [this replaces the core rule's Com+6 limit], or +(Com+6) for a Good Teacher. Whether the summa is on an Art or Ability, the increase to quality is +1 per level lowered [this replaces the core's +3 increase to quality per +1 decrease in level for Abilities]
....
Covenants presents many more options, which you may have access to with the following caveats.
As noted, resonance may be applied to any text, not just mystical ones, but provides only a +1 bonus. Unique objects gained by adventure may have any affect on the book, decided on a case-by-case basis. Clarification isn't allowed.
Exemplars and Juvenilia are simply works that are copied quickly, as per the rule above.
Congregationals cannot be used to study from simultaneously, nor used as communal casting tablets. They are just very large books.
Palimpsets grant the book a -3 to quality and deny both superior scribing and illumination.
Florilegia are not allowed, nor do Folios increase the quality.
Magical Nourishment
Food created magically (except by a Momentary Creo Ritual spell) does not provide nourishment. It can satiate hunger, but not provide nutrition and energy. Likewise thirst may be satiated, but deprivation of water remains a problem. The hunger (or thirst) of those subsisting on such food (or water) might be alleviated, but they still suffer all the normal (mechanical) effects of deprivation. Intelligence rolls might be required to ascertain what's going on, subject to SG fiat.
Aegis and Items
Enchanted devices with active effects entering an Aegis of the Hearth are affected much like spells cast from outside. If the activator of the item isn't part of the Aegis or an invited guest the effect's penetration is lowered by the level of the Aegis. If this brings the penetration to below zero, the effect fizzles.
Similarly, items activated inside the Aegis are affected much like spells cast inside it. If the Aegis would have suppressed the wielder's spellcasting, the effect's penetration is lowered by half the Aegis level. If this brings the penetration to below zero, the effect fizzles. Items that trigger without a wielder, including unitentional triggering, are suppressed in this manner if they weren't within the boundary when the Aegis was cast.
Try this: you have only one casting total and have to distribute it between the copies you cast.
I'm happy you like it.
For further development the magic resistance special ability from mastering doubles only the parma magica.
And it is in paralell also with my other house rule by which the magic item penetration means only 1,5 point instead of 2.
I dislike this MR ability because the typical combat specializations are almost useless. For example you can easily learn BOAF and get an MR specialization. Was this a goal of the authors. Who knows?
Interesting, very interesting.
Ah, yes, forgot about that. +2 per level is clearly too powerful, not sure if +1.5 or +1 is best. I'll definitely add such a rule, though.
I really like your rules. 
Well, IMS learning BOAF would not be so easy so wielding it against anyone not specializing in fire magic (or Creo or so on) would probably still be useful. It does render typical combat spells less useful, true, but that's clearly the intention - to grant magi that are versed in combat high resistance against the staple spells. For this purpose, I think doubling the MR instead of the Parma is appropriate; MR can be fairly easily breached anyways (with raw vis, if nothing else).
Given the amount of work you've put into these rules and making them available on the Web, I would encourage you to submit them for inclusion on the House rules page of Project Redcap.
Change the DOE guideline, If i recall correctly, by the book, a level 3 DOE (voice, base 1) would do 10 points. Have it only do the base amount, or do the spell level in damage (eg: level 3 would do 3)
When I'm done with the site, which should be in a week or two, I'll submit it to Redcap, and the House Rules page along with it.
I don't feel any such "I'm being cheated" feeling - I feel it worth noting that I'm never had my own magus learn the spell - he never felt it worth his (very valuable) time.
I do still feel that the spells are useless if they can't do anything at all. As YR7 points out, as long as the spell lasts, the person should be unwakable.
And for the moment of the duration to last long enough for the person to fall to the ground is quite reasonable. (Mind you, if there is a battle going on, he'll be waking again rather quickly - but will still be out of action for a couple of rounds). When cast on the guard standing nightwatch, there is very little to wake him...
The very big problem I have with scent to slumber is that it is an instant kill spell. (OK, come shooting with examples why it is not, but in all reason: a sleeping person is as good as dead in most cases and) Besides that it is a lot more usefull, since you can kidnap people instead of killing them.
Everyone can kill a sleeping person, certainly if they are allowed to stab 10 times.
The biggest problem is that low levels needed. So if you take a hefty base (so that he doesn't wake up from noise/damage) and a duration greater than momentary, you should end up around lvl 30 minimum.
Low-level sleeping spells require some extras, which makes them very nice only if used right. If someone is already laying on the ground the spell works wonders, if your accomplise will catch him when he falls unconsious it works too. But such requirements make the spell a lot less overpowered.
Good to hear. (I do have to wonder why you "quoted" my entire post, when you were only responding to single last sentence though... )
The point is that that spell is nearly useless, depending on how a SG interprets "Duration: Momentary" - whether that's long enough to hit the ground, or not. If a "momentary" spell can send a dart to a target at Voice distance, or ward a round's worth of attacking ("one" attack") from a weapon, then it should(?) be long enough to last until after the target hits the ground. Otherwise, as ulf points out, that canon spell can only be used against reclined targets - hardly popular enough to make the examples.
But if that interpretation doesn't fit for that saga, then that's the way it goes! Just as in another current thread that is discussing Arcane Connections, some examples in the book are negated depending on how the SG/Troupe houserules a given effect or instance. And houserules have different reasons behind them- it's what works in that Saga.
One obvious "rationale" behind the counter-argument would be that the spell says it takes "a few seconds"- as the target gets that sleepy, they would naturally sit/lie down before feeling the full effect. (This doesn't help the horseback situation, though...)
(??? - "low levels needed"... for what, again? Not following you, there.)
Well, CtS is Level 10 as written; add one magnitude for Duration:Diameter, and you get 15. Me, I like the Group version, Call the Group to Slumber, so that's Level 25. Don't see ~much~ need for more, tho' Sun could be handy for some situations, and Range: Sight would certainly allow for quieter casting...
As for the instant kill, well, yes and no, depending on the situation. If against 1 man, it still takes a minimum three rounds for that kill - cast, move, dispatch - hardly a spell that kills, or kills efficiently at least. And that means that if there are more than one opponent, all have to be slept in order to wander over and start slitting throats. Then, it's still time consuming- and a good SG might have allowed a cry of "Alarum!" from one, even if the Voice range didn't alert someone else of the problem.
If the mage is retreating, in a hurry, on horseback or it's otherwise "awkward" to stop and slay the enemy, then it's not "instant kill", not at all. An "instant kill" spell does the job all by itself, no need for any "mop up" activity.
But what does that matter anyway? Killing an opponent only makes life worse half of the time- with constant suspicious deaths, Quaesitores could get involved, or blood feuds start, or something unpleasant that will make the mage regret slitting those unnecessary throats. It's not like it's a certain other game, where you only get XP if you "kill the monster".
I would suggest increasing the base level required to make someone sleep rather than interpreting the spell to make its effect be broken easily even though the duration lasts 
Change the guideline instead of changing how magic works.
There are some instant killing spell beyond the sleep. For example changing opponents into babies. What about them?