So you would give the spell the same level even if it was designed to prevent future transformations as well?
I would give the principal reversion spell/effect that level yes. If you consider that the body would keep trying to change after it was magically prevented from doing so the first time, then I can think of a number of arguable issues...
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The spell should then be a momentary effect rather than Sun (which it was made to be in order to resolve the very issue you suggest) since apparently you don't hold that a condition, once met, is maintained for the duration of the spell/effect with which it was met.
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Given a momentary Duration, there should then be (as I originally suggested) a separate watchdog InCo(An) effect which would continuously trigger the Forestalling effect throughout the lycanthropic period.
I personally consider the spell sufficient to prevent and continue preventing the beastial transformation once its initial conditions have been satisfied. YMMV.
I agree that Sun duration would be sufficient, as long as the condition is met at the time of casting.
What I'm more confused about is what condition has to be met in the first place.
The effect that Vetrenius ex Verditus designed in the first place at level 30 was designed to transform a werewolf in wolf form back to human form (as it was described anyway) at Sun duration.
The effect we're talking about now is one that can be cast as a precaution beforehand as well, before the transformation into wolf form takes place.
As you designed your spell it does both of these things at the same level as the effect Vetrenius ex Verditus designed, which means there would be no reason to create a spell without the precautionary effect as well.
Your spell effect takes into account two possible conditions at the time of casting at no additional cost:
- the lycanthrope is in wolf form
- the lycanthrope is in human form (but might transform into a wolf at a later stage)
This would in effect mean that mean_liar is right in his interpretation, or merely that one would have to change the wording of Vetrenius ex Verditus's spell to give it an extended effect (the one I presume he intended in the first place).
Do you see my point?
No, my spell is designed to take effect upon the condition of the lycanthropic transforming actually taking place. As I have now alluded to twice before, I do not personally consider this effect to be a stand alone effect, but one which requires some monitor effect to which it would be linked.
When the human is in the process of transformation, the watchdog effect would sense the animal nature arising and would resolve the crisis by triggering the forestall effect thus reverting the target back to his/her natural form and maintaining him/her in that state until the effect expiry.
Since there can be no lesser effective Duration (as per the original design) than Sun regardless of the fact that the lycanthropic period only lasts 6 hours or so (midnight to daybreak), one must either concede that the forestall effect has met its condition at the moment it is triggered and thus prevents any further attempted beastial transformations for the entire lycanthropic period, or else one should design the Forestall spell as a momentary repeatable effect subject to multiple triggerings over the 6 hour period.
Does that clarify my position sufficiently for you?
That clarifies what you meant, I think, yes.
You are saying that your spell design would still need a separate watchdog trigger effect in order to work as a precautionary effect.
This is in my opinion exactly the same effect that Vetrenius ex Verditus designed in the first place though, except that you need a different triggering mechanism.
What I was asking for however, was if it was possible to create an effect in a spell (or in an item, where it was triggered twice a day) that prevents the target from transforming within the Sun duration even if you cast it before the transformation had taken place.
This would of course be a lot more useful in many ways as it could be cast as a simple spell beforehand, or invested in an item without the need for a complicated detection and triggering mechanism.
I understand I should have made some things clear, as everybody sees werewolfes differently.
At least Hedwig transforms at the beginning of the night before full moon, stays in wolf form for the next day and night, reverts to human form at dusk and reverts to wolf form for the following night.
As SG I left it open whether this is only the case in Hedwig or all Werewolfes. The Characters have not yet met another Werewolf for more than a few minutes. (And will be happy to avoid any further contact to the Werewolfes of Pomerania!) 
So for Hedwig the triggers will be sufficient as described, IMO. On days outside this period she may or may not wear the necklace.
As for Warping: Hedwig is part of the Magic Realm having a Might Score of 20 in wolf as well as in human form. Thus, she will not receive warping due to magical effects, IMO.
Thats what I clearly wrote, yep. 
Maybe, I was so busy just dealing with how I interpreted YOUR question, I more or less forgot about poor Vetrenius' original post lol. I was aiming for maximum efficiency more than anything else.
Well that would be more difficult if not nigh impossible IMO, since Lyncanthropie is not a magical transformation but a supernatural one and as such is outside of the scope of simple Hermetic effect/spells to detect or resolve easily. Thus my suggested two effect system.
As you rightly state in your earlier post, the necessary condition for any Hermetic solution would not be met whilst the target was in his/her natural human form. As such there would be no hint that the target was prone to any malediction or hereditary anomalies (however one wishes to view the acquisition of Lycanthropy in their sagas), so magic could neither detect it or prevent it as I read the RAW. Even an InMe effect to read the target's mind would fail since Lycanthropes classically have no memory of their beastial transformations.
Indeed it would but Im afraid unless I see a valid argument to the contrary, I would say that this is just another example of the limitation of Hermetic magic.
I think there's some details to be filled in by the SG on this.
A shapechanged human in the form of an animal with an animal mind still requires Mentem to affect them (AM p117, Animal Spells). Then it goes on to say that Heartbeasts are animals and therefore a changed Bjornear would be affected by Animal spells.
Part of the problem is that its unclear if the Lycanthrope is actually an animal or a shapechanged human.
By my interpretation I don't know if a mental restoration is possible in this case. The MuAn effect described doesn't necessarily prevent the transformation, it overrides it, turning the human-as-animal back into a human form - you'd need a Perdo effect to shut down the transformation, not Muto.
If the base effect is Muto I still think you'd need Rego, since the transformation has occurred and you're only treating the symptoms. MuAn (Me) plays with the target's memories and emotions and really you'd want to "incline a person to a certain kind of response", a Rego effect.
Neither being part of the magic realm nor having a might score will prevent Hedwig from gaining warping points for being subject to a 6 magnitude continuous effect. She is immune to warping but not to the eventual possibility of Twilight from cumulative warping points. You need to pay attention to that distinction and keep track of her WP accumulation.
Your novel multiple/protracted period interpretation would make Hedwig's reliance on such an item rather costly in WPs over the course of a year as she would gain 1 point every time the effect was activated - which would be 3 times (nightfall day 1, again at sunrise day 2 and again at nightfall day 2). This would be 3 points per month, 36 per year!!! by end of year 1 alone she would have a Warping score of 3 (6pts), OUCH!!
I suggest you rethink her curse and bring it back into line with classic lycanthropy. Then at least she would only gain 12 points a year which is still nasty, but far better than the alternative.
Shapechanging is a voluntary act of magical or supernatural origin and as such is not comparable with Lycanthropy, which is an involuntary domination of the base animalistic nature over the rational human form, a supernatural curse beyond the victim's control.
As such, the victim is indeed fully an animal with the mind of an animal so Mentem would not effect them IN beast form, but then my suggestion for the req is concerned with restoring the human rationality to the human form (as per either MuMe: "make a major change to a person's emotions" or (as you rightly state) PeMe: "Quell an emotion in a person" (e.g. Rage) or probably most valid CrMe (use for "healing a mind" rather than instilling thoughts or raising mental characteristics).
Ah, now you're answering the question I thought I asked clearly in the first place, and that I was so busy finding an answer for in your replies that I misinterpreted your meaning.
You may very well be right here. But at least you wouldn't have to detect the lycanthropy curse if you already knew that the person in question was a victim. If a "Lock in human form" spell of Sun duration would work you could just cast it on the person you knew was a lycanthrope and wait for nothing to happen.
What I can't quite see is how this spell effect is less valid than one that transforms the werewolf wolf form back into a human. If the lycanthropy curse is beyond hermetic magic, wouldn't also this transformation be impossible?
Congrats on your 500th post btw!
Another magus casting it as a spell wouldn't necessarily have to detect the lycanthropy to affect it, but an invested effect in a device WOULD. That said,
well for starters, there is the fact that what we are dealing with here is a question of affecting in some way the essential natures of the target. In human form he/she is essentially human, in werewolf form, essentially animal.
I see no reference in the Rego guidelines by which I could construe an effect that would "lock in the human form" or that is to say "lock OUT the animal form". A ward wouldnt do it as that would just make the device fly off the transformed body of the werewolf when the time came. Movement and control dont apply and we arent talking about shaping a substance as would a craftsman, so that aspect is out.
When tinkering with the essential form of a target this requires Muto, as that is what Muto IS for. Thus IMO, we can only treat the symptom of the curse (revert the target back to human form ONCE the lycanthropic change commences) but cannot otherwise, through Hermetic magic according to the RAW, prevent altogether that change from happening in the first place.
Its a nice idea but it has no workable guideline upon which it might be based.
The reason I suspect that the Rego guidelines offer no such suggestion is simply because any target in its natural form doesn't need to be "maintained" magically, it simply is. Lycanthropy is supernatural precisely because it radically interposes an entirely different natural self sustaining form upon the sufferer (much I suspect the way the Bjornaer Heartbeast interposes the natural animal form upon the Bjornaer supernaturally (albeit voluntarily and without loss of the human mind), thus being a mystery not a hermetic effect)).
So what IMO is most efficient and effective is to arrest and reverse the transformation as it is occurring.
Thanks, hadn't even noticed 
You have me convinced. I just needed a logical reason why it would be that way.
This also means there is no way I would allow Vetrenius ex Verditus's item to work as he intends it, and definitely not with the lingering effect described by mean_liar.
Another way to go about this though would be to cast a MuCo spell with Sun duration on the lycanthrope that turned him into some other humanoid creature far more pleasant than a werewolf and a ReMe spell for a calming effect.
If these were cast at sunset they should normally last till dawn... the question is, would the werewolf curse override these spell effects? Or would the spells stay in effect suppressing the curse?
I personally have no problem with the theory behind Vetrenius' solution as it is (having taken a moment to refresh my memory of it) basically the same effect as I unwittingly duplicated during our back and forth on the matter.
The only alteration I would make, upon further reflection, would be to lower the duration to momentary with the InAn monitoring effect (only has to be level 14 actually (see below*)) in constant operation in the device. The reason being twofold, one is that it would circumvent the argument concerning the ability of a single effect to continue to prevent recurrence of the lycanthropic change throughout the entire danger period, and secondly it would avoid the accumulation of warping points by not being continuous even if it was necessarily reactivated many times throughout the given timeframe.
The only continuous effect would then be the InAn effect, but in this regard the target would only have to worry about 5 WP per year (1 at initial activation and 1 each season thereafter) rather than 1 or more per month.
IMO if the effect deals with treating the symptom of the curse then it would work just fine. Using the new thought I posit above the second question becomes moot.
Scrying the State of the Slumbering Beast Within
InAn Level 14
base 3 (Detect the state of consciousness of a beast), +1 Touch, +2 Sun, +3 environmental trigger Dawn/Dusk, +1 2 uses per day)
Link the Forestall effect to this effect for whenever it detects the beast awakening and you have your effective and efficient closed loop solution.
What I meant about not allowing Vetrenius's item, is the way it triggers. It needs that InAn effect you just wrote up. Otherwise his spell effect is just fine.
As for Momentary duration I'm not sure I'd agree. Sun rings better in my ears, or the night would be a constant spasm of transforming back and forth surely exhausting the lycanthrope completely. That's how I see it anyway. Isn't there also a limit to how many times an effect in an item can be activated during a day unless you power it up to unlimited, which increases the cost.
The MuCo effect I described in my previous post was not one specifically aimed at lycanthropy, no. It could also be a spell transforming the target into a rock. The question is would a lycanthrope under the effect of such a Muto spell remain a rock for the duration of the spell as normal, or would he still turn into a wolf at full moon?
If you had the Lab Totals you could do this as...
Feeling the Beastly Change
InIm 4
R: Touch, D: Sun, T: Ind
This effect "watches" for lycanthropic change by detecting sudden hair growth by touch.
(base 1, +1 Touch, +2 Sun; +3 environmental trigger Dawn/Dusk, +1 2 uses per day)
As an item it would require a level 8 effect and would give your Forestall a detector that wouldn't cause Warping, since its the item undergoing the constant effect rather than the wearer.
The wearer would have to keep skin-to-skin contact with the item but that shouldn't be a large concern. I tried to do it as a vision effect but making it Sight range and giving the ability to see in the dark was too much effort - the final total was 34 I think.
Nice alternative!
Not true actually. The only way you could call the the Target "the device itself" would be to have a Range:Personal. Insofar as you have a Range:Touch, the Target of the effect is (and would needs be anyways) the wielder of the device. Thus you cannot circumvent any warping points for constant effect, all you can do is minimise them down to 5 per year as I have done and you have done even more efficiently, nice work!
The justification is that it fits into the story much better this way. I do not like to tell too much, as several players of my troupe will be reading this.
Twilight is a specific reaction to warping of hermetic magi. Other traditions will have different ways of reacting towads warping. Thus Hedwig will never experiance twilight. That is, unless our criamon finishes her research to take all people into final twilight to relieve them of being reborn.... 