I believe something like this can be done with faerie magics (core, p.92, possibly HOH: MC, otherwise RoP: Fae).
Or you can use ReVi to create a spell that contains a spell (eg. Watching Ward, core p. 162).
If you add both Intelligo and Mentem requisites, it should work (or Intelligo and Corpus to watch for an action). You also need to remember to use the highest base level for all the effects in the spells: reading a person's surface thoughts is Base 15, for instance, while marking their forehead is Muto Corpus Base 2 (I think). So if you want a mark to appear on their forehead if they think a certain though, the spell is InMe with MuCo requisites. And if you want to add some good old pain to the mix, that's PeCo base 4, so you need to add one additional requisite.
Mark of Justice : brands anyone who blasphemes (replace with whatever you want to punish) while in the circle, in word or in thought, with a mark on their forehead, and also causes them great pain but no real damage. Both mark and pain go away at the next sunset or sunrise.
In(MuPe)Me(Co) Base 15, range Touch, Duration Sun, Target Circle, +3 requisites, +1 fine detail (because you would normally need a Part target to place the mark on the forehead, but you are already using a Circle target...), level 50.
The above might not be accepted in all saga, as it constitute in part 2 spells effects into one (Reading thoughts + Inflict pain). I remember some discussions here about this subject. If it is, I believe the mark can be taken as a cosmetic effect of the pain (just like the pilum is a cosmetic effect of the fire being created, for exemple), thus saving 2 magnitudes.
As an exemple objection, if you allow spells such as the one below, some Watching Wards (such as the one below) become a lot less usefull (sure, the level is 2 magnitudes higher, but NO RITUAL!!!).
Depending on the spell, an alternative (and sure-to-be-RAW one) would be a Watching Ward, with a PeCO spell being linked to an InMe one.
Just checking so i know what to tell my player, but he would have to roll the lowest of those 2 tchniques and 3 forms to cast the spell, i got really confused when i read the requisites part of spell casting? (i have a feeling he's going to have to rebuild his arts and virtues to accomedate the spell casting)
The Fixer is correct. This is decidedly against RAW. It essentially violates two things in addition to the mentioned Watching/Waiting Ward problem. It destroys the whole conditional bit of Faerie Magic (HoH:MC). It also totally messes up a huge part of the linked effect (lab chapter) from the main rulebook.
That's not quite how requisites work; that's just a starting point. If nothing else is added to the effect, sure. However, if extra things are done, you need to add magnitudes on top of that. For example, Leap of Homecoming transports the caster. With requisites the caster's clothes are transported with the caster, which is essentially the same thing. However, the caster cannot transport the clothes only via Leap of Homecoming. Now if you look at Ward Against Mundane Intrusions, it is level 50, 4 magnitudes above Ward Against the Curious Scullion due to requisites because it stops those things separately and in addition to the original effect.
So if my paraphrasing of this whole thing is correct, i take the effect i want activated (assuming it's the highest) i put an InCo or InMe requisite at what? a +2 mag? I assume i don't need a ReVi req (like watching ward is) since it's the spell controlling its self. Theres no reason it needs to be a ritual unless it meets one of the usual requirements.
The way watching ward works would you have to research it again for every spell level? That seems kinda silly.
In the RAW, you don't invent a different Watching Ward for each spell you want to cast using Watching Ward. You just have a version that is of the same level as the spell you want to suspend or higher. The downside is that as a ritual, you have to use vis each time you cast Watching Ward.
No, not unless you want to make a house rule. There are four ways to do it via RAW:
Two effects, the primary one and an Intellego one, linked together in an item.
Initiate the appropriate Faerie Magic virtue from HoH:MC.
Watching/Waiting Ward. This is a little more limited than the above two.
Tethering, whether via a virtue or Spell Mastery. This is even more limited than Watching/Waiting Ward.
Requisites are not an option via RAW. If you want to house-rule them as possible, you should probably take a look a the Faerie Magic adjustment for the same thing, and then add another magnitude or two on top of that.
ok, so useing watching ward and messing around with it seems to be the bes option.
Now that raises another question, How does the damned thing work? do you cast it then cast other spells at it? do you cast it right after you cast a spell on the spells target? Do you just imbue the ward with another spell when you cast the ward?
The book seems to imply that the suspended spell is cast first. but how would that work with a fireball or somthing like that? It uses the terma "included" and "put in" that seem to imply the other two though.
Doesn't Frosty Breath already do this sort of. By my reading, if the discriminator effect (detect lies in this case) is the main effect, then it's a mentem spell and the breath, being a merely ancillary effect, is just a requisite.
I suppose, IMS, if someone wanted to try and 'double up' on main effects, then another solution would have to be designed,... most likely an item.
There is a lack of clarity on this part (mostly with MuVi spells), but it doesn't make much of a difference. You cast both spells, one after the other. Since one is a ritual in this case, it doesn't really change the casting time in any noticeable way. If I recall correctly you do the MuVi or ReVi spell first, then the following spell.
The breath is how the lie is detected. It is nothing in and of itself and can't be used to do anything except identify the lie. Notice there is no requisite. As was already pointed out, this is for legacy/sigil reasons.