Did I build this spell right?

[Jack B]

Okay, here's the situation.  Probable bad guy(s) have an item of power and are going to charge it by the light of a full moon (3 days hence) at a known place of power.  My wizard wants to stop this and he and his buddies will try to confront the bad guy(s) and get back the item.  One problem we have though is that we have no idea who it is or how powerful he/she/they are so I want a back up plan. 

The plan, a thaumaturgic spell that will block out the moonlight and create an illusion of moonlight so that the item can't get charged and no one will know why.  The site is a place of power with 1 zone of size.

Here's how I stated it:

Block:  Moonlight energy only.  +2
Veil:  To appear as the moon would appear.  +12 (judged on a conservative guess of alertness/lore +6, +4 for the roll and +2 for an aspect)
Size:  Cover one zone +2
Duration:  a few days +2

for a total of complexity 18. 

Also, how would this spell be taken down?  Would it have to be dispelled with a power 18 counterspell or it's thaumaturgic equivalent?

[Papa Gruff]

Okay, here's the situation.  Probable bad guy(s) have an item of power and are going to charge it by the light of a full moon (3 days hence) at a known place of power.  My wizard wants to stop this and he and his buddies will try to confront the bad guy(s) and get back the item.  One problem we have though is that we have no idea who it is or how powerful he/she/they are so I want a back up plan. 

The plan, a thaumaturgic spell that will block out the moonlight and create an illusion of moonlight so that the item can't get charged and no one will know why.  The site is a place of power with 1 zone of size.

Here's how I stated it:

Block:  Moonlight energy only.  +2
Veil:  To appear as the moon would appear.  +12 (judged on a conservative guess of alertness/lore +6, +4 for the roll and +2 for an aspect)
Size:  Cover one zone +2
Duration:  a few days +2

for a total of complexity 18. 

Also, how would this spell be taken down?  Would it have to be dispelled with a power 18 counterspell or it's thaumaturgic equivalent?

I'd say you got it mostly right. Only one thing I see:

A Veil is usually set up as a block against Investigation/Alertness. So I'd probably strike the +2 shifts you stated to resemble that it is a block, because Veil = Block. The rest is flavor of narration.

So the spell would come down to 16, witch is quite hefty. The block has to be broken one way or the other to circumvent it's effect. Either by beating its value through a skill-roll (witch at this level of power is unlikely) or through a counterspell that meets its power-level.

Attention! What follows is nitpicking: Why would a Wizard do something this complex in this situation? The ritual can be stopped or interrupted far more easily. Several things come to mind: circling it with a secondary circle, interrupting the circle of the ritual or disrupting the casters attention at a critical moment for example. Now ... if the goal is to make the perps think the ritual was a success, then never mind. Question is: Why aren't the ritualists noticing that the IoP isn't getting charged?!

[ironpoet]

I think those stats are perfectly reasonable.  I would personally require more than two shifts to block the moonlight, since we're assuming that this "Full Moon Light" is strong enough to power this Big Bad Item Of Power.  I'd probably set it at six shifts for the block.  I'd also set the base duration as "one scene", so you would need more shifts in order to work for "a few days".  But all that being said, statting spells is a pretty subjective thing, and I think your take on it is as good as mine.

Counterspelling thaumaturgy, mechanically, requires an equal power counterspell.  I'm not a huge fan of that mechanic, though, since it means that more complex spells are harder to disrupt than simple spells ("This computer is harder to break than this cannonball").  So I might houserule than individual characteristics of the spell could be counterspelled.  Therefore, if the veil was detected, then a +2 (or +6) counterspell could break the "blocking" aspect of the spell, leaving the veil in place.  Alternatively, shifts could be use to decrease the duration of the spell, so that it would end while the moon was still full.

[devonapple]

I'd also set the base duration as "one scene", so you would need more shifts in order to work for "a few days".  

And just to be clear, is one scene is usually considered 15 minutes, or half an hour on the Time Chart?

[Jack B]

Like I said, this is a back up plan in case we're not able to disrupt the ritual for whatever reason.  I would like it to be passive so that it's not particularly noticeable so that the bad guys spend their time on a ritual that won't work instead of counterspelling the veil/block.  I assume that with enough time the spellcaster can work up enough maneuvers/declarations to create a counterspell that works even if they have to spend a couple hours to do it using thaumaturgy instead of evocation.

Also, what I didn't mention is that the item of power won't actually be charged by the moonlight but it will be prepared to accept a charge.  Kind of like priming the item's pump.  That's why I figured a block of 2 for the moonlight should be more than sufficient.  I was debating if the veil itself blocks the moonlight to, because like you said a veil = a block but I figured flavour wise it seems neat to block all moonlight energy and create something that only appears to be moonlight.  I'll talk to my GM about this first of course.

I figured that the time would be 'an afternoon' since the base time for a thaumaturgical spell is until the next morning.  2 bump-ups later brings us to 'a few days'.

[sinker]

It all looks good to me, but I would talk to your GM about blocking the moon's power, he's (or she's) the one who would be able to tell you how much you need for that.

[Papa Gruff]

@ironpoet & devonapple

I think it's reasonable to assume that most thaumaturgic spells start at a time frame of "until sunrise". at least that's how it feels in the books. but that's for everybody to decide for them selfs.

[devonapple]

@ironpoet & devonapple

I think it's reasonable to assume that most thaumaturgic spells start at a time frame of "until sunrise". at least that's how it feels in the books. but that's for everybody to decide for them selfs.

It's a tricky one. "Until sunrise" is the most commonly mentioned base duration for thaumaturgy, but I believe that applies to immovable things like wards and veils. Harry's tracking spell, for instance, assumes a base duration of "One scene." So in this case, you are correct: it would be better to use "until next sunrise" (since this is a series of immobile veils). My apologies.

But for other thaumaturgic applications, I recall that there is a line somewhere else in the rules about certain effects being more appropriately measured as taking up a scene in duration, but it can be a tricky one to find. I'll have to hunt it down. Perhaps mobility of effect is the determining factor between "until sunrise" and "lasts for one scene"?

[UmbraLux]

Here's how I stated it:

Block:  Moonlight energy only.  +2
Veil:  To appear as the moon would appear.  +12 (judged on a conservative guess of alertness/lore +6, +4 for the roll and +2 for an aspect)
Size:  Cover one zone +2
Duration:  a few days +2

for a total of complexity 18. 

Also, how would this spell be taken down?  Would it have to be dispelled with a power 18 counterspell or it's thaumaturgic equivalent?

Dispelling it would presumably require at least 14 shifts (moonlight + perception blocks) and possibly the full 18 (I'm not clear on whether dispelling needs to cover duration and area shifts.)  And noticing the spell would require 12+ shifts...  However, if it is noticed (and analyzed), it can be pierced fairly trivially.  Opening a temporary hole in the moonlight block would only require 2 shifts plus enough to cover the needed duration.  If time isn't an issue, it might be worth making that more difficult.

@Papa Gruff - I see it as two blocks, one against the moonlight and another against perceiving the spell.  So it probably needs those two shifts.  Of course that is dependent on GM. 

[Papa Gruff]

But for other thaumaturgic applications, I recall that there is a line somewhere else in the rules about certain effects being more appropriately measured as taking up a scene in duration, but it can be a tricky one to find. I'll have to hunt it down. Perhaps mobility of effect is the determining factor between "until sunrise" and "lasts for one scene"?

Touché... Especially the last sentence seems reasonable.

An other idea is, that Harry's tracking often relies on a mediocre spiritual link, blood that drys fast, a single hair, etc. That's not much to work with and may deplete faster then other spells. Perhaps that's why it's stated like it is, because Harry has to cautious of his recourses ...

[Papa Gruff]

@Papa Gruff - I see it as two blocks, one against the moonlight and another against perceiving the spell.  So it probably needs those two shifts.  Of course that is dependent on GM. 

That is ok. It's possible to build it like that. Perhaps as an extra precaution even...

[devonapple]

Found the requisite quotes on YS 266:

"So a curse that acts as a maneuver to put Bad Luck on a target might start from “15 minutes” (about the length of that particular scene), and you could make it last all day by adding five shifts of complexity to the spell. Duration can be applied to a spell in a flexible sense—how long the energies will hang around until triggered, how long a particular effect will last, and so on.

If the default duration is not clear (such as curses that are cast on a location, or a ward that doesn’t express its effects in terms of aspects) use this guideline: thaumaturgic spells typically last until the next sunrise, as this cycle weakens magical energies. So increasing from there would start at “an afternoon” or “a day” on the time chart.

Again, this “until sunrise” default doesn’t apply in the case of spells that inflict consequences or temporary aspects on a living target—in those cases the duration of the effect behaves normally. Also, consider that the consequences and other aspects in those situations are often the result of the spell, but they aren’t sustained by the spell. Attacks of that kind don’t really have an intrinsic duration—they just happen, and they’re done."