I am designing a steel sphere as an invested item to work like a wrecking ball. Size issues aside, I want to have mental control over the ball.
As I’ve read in other topics like this, it must have some kind of trigger—either environmental, a spell, or something similar.
In my case, I want to be able to control the sphere while I'm invisible. What would that imply, and how could it be done? Would it be possible to have another item act as a sort of focus or key—like a ring, for example—so that the sphere only obeys commands from whoever is wearing it?
Also, any suggestions for other effects this wrecking ball could have?
you invent a ReTe spell to move the sphere at distance - you need a good Concentration and Finesse skill - Base 3: Control or move dirt in a very unnatural fashion, +2 for metal, Ind, +1 Conc, +3 Sight, for a final ReTe 25
you go for an invested item, with two effects: one that move the sphere, with the same base as the previous effect. Base 3, +2 for metal, +1 Ind, Self, +2 Sun, (ReTe 20), +1 (2/say), +3 env. trigger, for a final ReTe 24. And as a second effect, an InMe, reading the mind of the magi (base 15 (surface thoughts), +4 AC, +1 Conc, Ind, +5 maintain Conc, +1 2/day, +3 Linked trigger for an InMe 49.
I choose AC range for the mental link, so the sphere can be controlled regardless of the distance, and only by the magi. I also choose a duration of Conc, with a couple of activation per day instead of a continuous effect, as a continuous effect will trigger Warping in the magi constantly under the effect of a mind reading spell. So the magi needs to trigger the reading mind spell, after wards, he has unlimited control of the sphere.
Because the sphere is an enchanted item (or an item under magical effect), the ReTe effect needs to have a good Penetration to affect any target with MR.
You could also go for a ring that has two effects:
Read the magi's mind (same effect as above, but with a range of touch +1 instead of AC +4, for a final InMe 34
Cast ReTe 25, with +5 maintain concentration, and +3 (6/day), for a final ReTe33.
In all case, you need good Finesse, that's what drives the accuracy of your control. Because of the mind reading effect, it is silent, so the invisible mage won't be noticed.
Depending on the size of the ball, +1 for size could be required.
It's a Wreck Ball so don't invest it as a magical item. Just learn a few ReTe effects and sling it around.
One to Fling the Wreckball and most likely kill/destroy what it hits. No need to penetrate as you just do a finesse aim roll.
One to transport it akin to what @Ezechiel3571 but slower and thus lower level
One that is concentration and you make it hover your Target and end spell allowing it to free fall and crush all that is under W/O magic resistance to worry about
I guess you could invest into the ball a fling effect to have a similar effect but why would you? The spells allow you to use it on the Ball and any other material that is similar.
Then, it the concept works for you, make it a Talisman and then add effects where it becomes a Ball of Fire with lots of penetration. Or have it increase its size, etc. The Talisman part will allow it to have magic resistance of its own and makes it easier to invest effects into. Just remember it is also an AC to you.
Could have the ring enchanted to control the ball, as mentioned, or even have the ring CREATE a giant wrecking ball as part of its enchanted effects. Remember that if you're controlling something stealthily, you need it to be Sight range rather than voice, because you don't want to yell at it to make it move. Only goes as far your voice, after all.
A downside to that approach is that the wrecking ball damage becomes resistable. A normal wrecking ball can drop on someone under gravity: no resistance, just a targeting roll.
Does the Resistible Wrecking Ball problem apply if it's just a normal-sized rock most of the time, that you can make massive? That might at least make it more functional to carry around. But I don't know if being magically big means it can be Parma'd.
That said, you can still use it on a building, which almost never has magic resistance, and let gravity do the work (that you aren't aware of because it hasn't been invented yet)
Try it the other way: take a huge, ordinary wrecking ball, and magically shrink it down for convenience. When it is crushing something, it is utterly mundane.
Gravity is an understood thing, though Newtonian explanations for it aren't. Yes, many useful targets won't have magic resistance at all, it's not a deal breaker.
I believe a small ball made magically big can be MRed. The workaround is to have a ball that is naturally big, but is kept magically small until you want to drop it on someone.
That said, "Small ball that becomes big sometimes" feels FAR LESS PRONE to unfortunate botches or suppressions than "Big ball that you have to continually maintain a smallness upon"
This is one of those things where's its easier to make it a spell than a magical device because of the extra hoops you have to run through as a magic device. But I can see some issues:
1.) the mind reading spell on the device needs to run on AC range (so it must have an AC) and it should have Penetration unless you're willing to lower your Parma when a fight breaks out. This means it's a pretty beefy effect total. You'll have to tailor it to the creator or it will cause Warping each time it's triggered (level 30+ effects)
2.) the 'move iron ball' iron will probably also need Penetration, as you don't know what has MR until you smack it. Yes, you can drop the effect to drop the ball naturally, but that means ending the effect, so you need more uses/day
3.) enchanting the iron ball to do the effects means the moment someone rolls out with PeTe effect your magical item is destroyed. Most magi keep magical items close to their body (rings, amulets, gloves, belts) so they're under your Parma, or enchant their Talismans (which get the full MR of the magi while he holds it). Rusted Decay of Ten Score Years is a PeTe10 and magi love it for turning swords into junk. Unless your metal ball is +1 Size (which makes moving it harder) it has a common counter.
My preferred solution would be:
1.) Lesser device to create a metal ball. CrTe, lots of Penetration. Use Duration: Diameter and you can always use Effect Expiry: 70 years (or even 7 years) to manage it in a single season. Give it a button-push effect activation (silent). Sure, 7 years expiry sucks, but you can use similar spell bonuses to make a better one later.
2.) Use a ReTe spell to move and control the metal ball*. Sight range is enough. If the ball leaves sight range, create another ball. Master the spell for Quiet Casting (x2) and maybe Fast Casting (to use it in fast cast defenses against flying metal objects). This also reduces botches on controlling the metal ball, but Mastery 3 is a tough sell without a virtue that boosts Mastering (Independent Study, Mercurian Magic). Quiet Casting 1 goes a long way for 1 season's work.
*Make it more general purpose to move a mass of metal if you like.
3.) Use Talisman Shape and Effect bonuses to boost the casting/Penetration of your ReTe spell
The even more preferred option would be to do this with a stone ball (or any stone), lower casting totals and you can grab random non-magical rocks almost anywhere, but I get the feeling an Affinity is in here somewhere.
Always keep in mind that an Invested Device is at least (1 + 1/effect) seasons, maybe more, so compare that with inventing a spell and mastering it to do funky stuff before committing.
If you go the lesser device route to create the ball, and if the ball being made of steel isn't crucial, maybe consider making it out of wood instead - most things will break if you hit them with a giant piece of wood, at least in the medieval era, especially a very hard, dense wood, moving at speed. And if they don't, you just hit them a few more times until they do. You're going to be conjuring another one in a few minutes so it's no biggie. The benefit here is that wood is Base 1, where Metal is Base 5. For the things you want in this effect, having as many magnitudes as possible to spare is good.
The Rego Terram will equally need a good Penetration. If the ball is pushed by the effect, constantly under the caster's control, both the magical origin of the ball and magical controlling effect can be resisted. Only Vilano's sling type effects are not resisted, that is an impulse giving motion to the ball, then no magical effect anymore. Thus loosing the control of the ball after it has been thrown.