That’s a very impressive magical tower the covenant just conjured. Cost a lot of vis huh? Shame if something were to happen to it. You need some insurance.
You know, just in case…
Terram is a wonderful Art in Ars Magica because of how prevalent it is in daily life. These spells are reasons why powerful wizards should be feared by fledgling covenants.
The first spell designed for destructive potential against stone structures, and the effect can target any baser Terram materials including stone of almost any size. As such the spell could be useful in a variety of ways. If a fortification was so massive that it could not be affected totally, the spell has flexibility in-built so it can destroy a segment of the structure, or the ground beneath something. It is not a spell that would get used to it’s maximum potential often, but the potential is needed for a powerful Terram magus.
Plentiful Destruction of Earth, Sand, and Stone
Perdo Terram 40, R: Voice, D: Momentary, T: Group
This spell destroys stone or weaker material, be that a single stone magically shaped (akin to Conjuring the Mystic Tower), or a volume of individual stones and rock, or part of a larger object or surface, or objects gathered in a group.
This spell affects up to 10,000 cubic paces of stone, or 100,000 cubic paces of weaker Terram materials such as clay, sand, dirt, or mud. The form and shape of the material to be destroyed is chosen when the spell is cast.
(Base 4 to destroy stone, +2 Voice, +2 Group, +3 group size increases, +1 flexibility)
The choice of spell design to use a Group target with increased mass is deliberate to affect mundane multi-stone buildings and structures crafted with magic. It would have been a few magnitudes less to destroy just the tower as created by Conjuring the Mystic Tower, as the tower is created as a single piece of stone (it could be designed as a level 20 effect instead of level 40 – see below). However the increased magnitude is reasonable to gain more utility for this spell. The effect could also be delivered at range Touch, however the rest of the structures contents and inhabitants are not destroyed so it is likely that the caster does not want to be close to the buildings destruction.
I took liberty of including all “weaker materials” in the same manner as the core Perdo Terram spell from RAW called Fist of Shattering, however limited this to weaker Terram materials. I like it when an effect can have breadth of use and the effect is similar to that spell. Likewise many spells use a broader target as their overall effect and also use a lesser Target as well – like using a Target: Group effect which also has a Target: Part component. Part is the default when targeting the ground and creating a hole, as demonstrated by Pit of the Gaping Earth. This was discussed in the forums and is generally acceptable, as the spell’s overall cost is based upon the more powerful and more expensive greater Target.
Because this spell uses the flexibility of stone with all its weaker Terram based materials, allows the size and shape of materials chosen when cast, and also uses allows a sub-part to be targeted like Pit of the Gaping Earth, I’ve added a +1 flexibility modifier to the spell. The largest pit created by this spell is hundreds of times bigger, and likely to devastate the area it is used.
Each of these options in isolation are not worth an increase in power. Having this degree flexibility is beneficial though and makes the effect more complex. Conversely it adds a small cost because of the higher spell level and therefore worse penetration.
As a comparison to a far more simple spell, this effect is tailored for destroying a building conjured with Conjuring the Mystic Tower.
Destroy the Mystic Tower
Perdo Terram 20, R: Touch, D: Momentary, T: Structure
This spell utterly destroys a single building or structure made from stone. If the structure contains composite materials then only the stone is destroyed, but the effect on any building will likely be extreme.
(Base 4 to destroy stone, +1 Touch, +3 Structure)
The core spell End of the Mighty Castle (p.155) is the same effect at Range: Voice; which is a wiser but higher level. Given how rarely the spell might be used I think slipping a magnitude down is better.
See further custom spells for Ars Magica can be found in the summary spells page, particularly the other Creo and Muto Terram spells which complement this spell in a Terram Magi’s grimoire.