My question: How would you calculate the effect level of a Goetic Binding when you try to figure out the lvl of PeVi Dispel magic to dispel it?
My problem is that as you become stronger in Binding as your Rego and Vim go higher it would be more and more problematic to dispel your own Binding - AKA control your own power.
A, Calculate the lvl of Binding based on the Might of the creature you bind?
B, Calculate the lvl of Binding based on your full Binding Total?
C, Can you use only part of your Vim/Rego score to generate lower Binding totals which can be dispelled more easily?
D, Can you choose not to use your Penetration ability to generate lower totals?
I don't see the problem with your Rego and Vim rising. What determines the difficulty to dispel a ReVi hermetic effect is the magnitude of the spell, not the caster's casting total.
I'd use the Binding Target Level (which is the Might of the creature).
I'm not aware of a hard rule on this, so it's up to the SG. You could argue it's the Might of the creature, you could also argue it's the binding total... All depends on how difficult the SG wants to make it to dispel.
Usually, the casting total for these kind of effects will be superior to the effect level, due to the need for penetration.
We could even say that, for anything relying on Arts, the case when casting total > effect level are the majority.
When targeting an effect, it's that effect's level that matters, not the caster's casting total. In short, you only need a low-level PeIg spell to dispel a Lamp without Flame, even if it was cast by a master of CrIg magics with a MMF in Fire.
So I'd say the Binding total is irrelevant.
Now, what's the effect's level?
IIRC, there are 2 cases for Goetic "arts" (iirc, they are more like Accelerated Abilities):
1- If the demon is in a summoning circle or such, you only need to beat it's might
2- If the demon is outside a circle, you need to beat twice its might.
I don't remember properly, but it seems like being in a circle either means that your effect don't need to penetrate (because you're already "in"), or that you don't substract its level from your penetration total.
We could be able to tell which is what if the Binding level was different of the Penetration required. We ain't, which means that Binding level = Penetration required = Might of the demon.
I am OK with the concept that Binding effective lvl = Might of Bind Creature.
But next question is what if Summoner B tries to re-bind Summoner A's bind spirit? If we use "Binding effective lvl = Might of Bind Creature" rule the 2 binding effects are the same lvl. I think in this case the Penetration would be decisive, but how?
Ex: Summoner A summoned and bind a Might 15 spirit into a pebble. A's Binding Total was 32 against a Might 15 spirit. The effective Penetration would be 17 - if needed. The running effect lvl is 15, right?
Summoner B tries to summon the same spirit, because she has the pebble. Does she need now beat the effect lvl 15 or the Binding Total of 32 with her Binding total?
If Summoner B wants to dispel A's effect, does she need to dispel against 15 lvl or 32 lvl?
This about two summoners competing is actually an issue about what to do with conflicting effects. For example, if two hermetic magi cast "The Unseen Porter" with conflicting orders, how do you determine who wins? There is no clear RAW, and I believe there isn't a single solution that works for every effect/spell, it needs to be analyzed case by case.
I agree with ErikT's view that you can't summon a bound spirit (it simply isn't free to respond to your calling), and that dispelling the binding would be lvl 15 in your example.
Note that if it is bound to an object you can release the spirit by breaking the object (and then you could summon it normally). For the specific example you gave, you have the pebble in hand, so I'd say that you can break the pebble and summon the spirit "at the same time".
If for some reason summoner A and summoner B try to summon the same spirit at the same time:
if the spirit was summoned within a circle, I'd say first come, first serve (because once summoned the spirit can't freely leave the circle)
if the spirit wasn't summoned inside the circle, it could be summoned by another person, since it's free to respond the calling
After reading the Ars Gotta for the 40th time, I realized that under Commanding they explicitly stated that the command "Begone" breaks the binding effect. I am happy and disappointed at the same time
Although it is not stated in the core rule, you could also consider that a mage has always an AC to his own spells, so he could benefit from a high Penetration bonus to overcome his own spell.
The reason I believe mages have an AC to their spells is the existence of Suppressing the Wizard's Handiwork. It is specifically tailored to affect a mage own's spell, so there must be a lingering connection between the mage and his spells, thus me inferring an AC.
I agree that it is a blurred area, entering the domain of house rule, so to be discussed with your troupe.
