Though I agree with your conclusions, I think that the problem with the reasoning is that Crystal Dart and virtually every other "auto-hit" spell are D:Mom, so one could argue that it's the magus who is actively "giving directions" to an otherwise dumb spell, so to speak. To make your case, you'd need a spell that makes something "keep going after the target" with some duration that's neither D:Mom nor D:Conc.
Just to start with a published guideline.
Cheers
A spell which keeps going after the initial casting, using Rego, which must adapt to external changes on a target is Controlled Growth (ReHe25)(MoH p39).
The caster decides what shape they want from a target plant when casting, and then for the very long duration of the spell (a year in fact!), the Rego effect restricts the shape the plant can grow into. It holds, restricts movement, and guides the growth while the effect is active.
It is not a 100% match, but then if it were we wouldn't need to debate it.
It is very close to the same concept, and supports the idea that Rego can hold an item in place, and also adapt to moderate changing conditions without either Finesse, concentration, or attention.
My problem with this is I assume that in ME we are able to use the concept of absolute position. In which case telling a spell to hold something in place, or move in a set way relative to that reference point is fine. But causing something to follow something else with its own motive power, seems altogether more complicated.
Bob
There is indeed an InCo guideline:
It also allows to identify a person by AC, without needing to start with the usual high level guidelines that use AC.
But you will have to use InCo requisites with your ReTe, which might not fit the character concept of ezzelino's 'fidanzata', and throw yourself at the mercy of your troupe by combining two guidelines in a non-trivial way.
Cheers
So you think it is implausible given the similar examples or just adds complexity in mags?
To which I reply a firm and definite "Um..."
Bob
The distinction I see with Coat of Flames, is that there is not a gap between the thing on fire and the fire.
I'm not sure, but I think the target Ind in that is (Using the base 5 guideline: Create a fire doing +5 damage in an unnatural shape such as... covering an item) is the individual being set aflame not the individual fire. (I am very easily prepared to be argued out of that).
Given that Casting requisites are by default not listed, I'm quite bewildered as to whether Coat of Flame requires casting requisites to coat objects which do not naturally burn, but not if they are intrinsically flammable.
So I can see that Sword of Damocles might need a corpus requisite to follow a person, but to me the adjacency of the Sword of Damocles makes this example not quite close enough to provide support, for not also need an Intellego requisite to follow at a slight distance a person.
Or maybe I'm over-thinking this.
Bob
Bob
No, the Target always matches the Form. Creating/controlling Fire is Form of Ignem. The (small-T) target, or as I like to call it, the recipient, is the thing affected by the Targeted Form. It's always the case, although in cases of Corpus, they do intersect and combine, but they are actually different things. Using different words for the "Form Target" and "Recipient Target" is something that the authors could've done a better job of doing to make this clear.
Make a wooden hilt for your sword, then use ReHe lvl 10 guideline like in Treacherous Spear.
Mythic wood, unlike mythic steel, seems to have potential purpose and intelligence.
FWIW, I see no problem tying an object to follow something by using an Arcane Connection at spell casting. Just because a spell uses an Arcane Connection does not mean it needs to be cast at Arcane Range. Just reword the spell, add the bit about needing an AC and move on. Perfect targeting and tracking, no finesse needed. And an AC, for this particular spell should be relatively simple to acquire.
If I understand you correctly, you would accept this spell:
The Sword Follows its Assigned Wearer ReTe 35 (R: Touch, T: Ind, D: Sun)
Has the item you touch move up to 5 paces to within a pace of a person or animal, of which you hold an Arcane Connection. If it is not a Terram item, you need to include casting requisites. The transported item will hover near the person or animal, and for the Duration of the spell follow it around at the distance of about a pace. It cannot perform precise or complex maneuvers. At the expiration of the spell, the transported item falls down. The spell does not need any Finesse.
(Base 4 [Nearly MoH p.92 or TME p.107], R:+1, D: +2, metal: +2, complexity: +2)
It is not cleanly derived from the quoted guidelines, and needs to be approved by SG and troupe - but yes, it looks plausible to me too.
Cheers
Rarely are AC's mentioned in the guidelines for spells, and then typically, it is for the spells that must be cast at R: Arcane Connection.
This is a good point you bring up.
I've been looking up guidelines and spells.
Both Corpus and Herbam have this "animate" Rego guideline, distinct from and higher level than "control", that allows the Target to behave with "purpose and intelligence".
Hence, animated corpses from the Corebook, and Severin's Carved assassins from ToME.
It can be argued that Animal corpses can get this too; as can Imaginem creations.
How about other Forms (without, say, turning them into a living animal, or using Mysteries such as Animae magic)?
Giving something level of intelligence required to obey simple verbal commands and be aware of the surrounding environment is apparently within reach of the other Forms too, for a meager +1 magnitude over basic control -- see e.g. MoH: p.111, Ranulf's conflagrative servant. Note that the fact that the conflagrative servant responds to verbal commands such as "wrap yourself around that creature" means that the magus is not directing the servant's actions through "telepathic control"; instead, the servant must be aware of the environment and act with a modicum of independent intelligence. So, assuming for Terram these extra "smarts" cost no more for Ignem, which is reasonable, animating a sword so that it follows a nearby grog for D:Moon, with sufficient intelligence to avoid low ceilings, to wait outside of a door etc. is at most Level 30 (Base 3, +1 magnitude for "smarts", +2 Metal, +1 Touch (remember, you need only touch the sword and you can tell it "follow that grog"), +3 Moon).
At this Level, you get more, in fact, since with the same spell you can give other commands instead ("whack anything passing through that door!") and you can change your commands if you grab hold of the sword before the end of the duration (remember, the command lasts even if the sword is out of spell range, but to change it, it must be in range). It's not obvious that you need the sword to be so smart as to require that +1 magnitude. After all, all you want is have it perform a single very, very basic task (following a person) with limited awareness of the environment.
In fact, it turns out you probably do not need that magnitude. One example was given by One Shot (and it's actually Rego Terram): it's Circular Wall of Shields, from MoH p.50. This animates (for D:Sun) shields to defend a "designated" person or group of people, around which they rotate slowly, providing total cover against missile fire, and some defense against missile attacks too. This means that the shields must be aware of the position of the folks they are floating around, and must move to block incoming attacks (if they moved slowly in a predetermined pattern, they would not be able to provide total cover for missiles and defend from melee attacks). Another subtle example is Petalichus' Bind Fast ReAn(He) spell (MoH p.100), that has "clothes seek out and bind themselves to the nearest other object, moving or not". The Duration is Momentary, but note that the magus need not, in principle, perceive where the nearest object is located, so it can't be argued that the movement is controlled "directly" by the magus -- the clothes must be sufficiently intelligent to detect the nearest object.
So, I stand by my initial assessment: a spell that makes a sword hang above the head of a nearby grog for D:Moon, is probably ReTe 25 (Base 3, +2 Metal, +1 Touch, +3 Moon) and certainly no more than ReTe 30 (with an extra magnitude for "smarts" -- though I'd say it's unnecessary). More generally, a "control" Rego spell can make an object move independently based on very basic features of its nearby environment, without extra requisites or magnitudes. This is canonical (admittedly, by MoH, which I'm not too fond of as a source... but still).
One thing the spell description should probably have is parameters for "breaking" it - like the core ReTe spell Hands of Grasping Earth.