Once again I'm thinking out loud. As mentioned in the smoke thread I'm interested in the idea of material components that help the caster. I can see a couple of ways to do this and I'd be interested in hearing if my thinking agrees with the general consensus. Sorry if it is long but a search brings up nothing useful related to the seeming solution (Spell Foci).
Design Task
A mage who can use shapes and forms to aid his spells.
This can apply to any spell if the shape and form bonus is applicable.
The mage is skilled with a subset of the shapes and forms such that it makes a clear distinction similar to that of a focus.
Thoughts
Special Circumstances could apply but it gives a flat bonus without regards to shape and form. The theme and feel is very different.
Potent magic works with the target not with the components.
Charged devices comes close. They could be handed out to others and get used up which really doesn't fit.
The talisman. It has some of the of the exact abilities that I would like but the feel is wrong in that it is a nice effect after you are already strong enough to make a good talisman but does nothing for you when you are weaker but playing in your niche.
Solution
Spell Foci (HoH S: 132) seems perfect. It allows the magus to add a spell focus into his spells when he creates them. The effect is to add one bonus from the shape and materials table to the CT when that spell is used. This is very similar to creating Potent spells except that a Potent spell gains an additional flat +3. The +3 reflects that the Potent Magic is restricted to a subset of spells similar to a Magical Focus.
The description goes on to say that the bonus can not exceed the mage's MT or his craft ability if he is using the Rustic Magus ability Craft Magic. My reading is that if the spell is being created using normal lab spell creation rules you would use any single shape and material bonus up to MT. This is actually broader that I want thematically but works mechanically. It's not as strong as Potent Magic but it is more broadly applicable with the same limitation of needing to create the spells using it.
I actually like the restriction to using a craft ability even for Hermetic mages. It acts as an XP/time sink (I'm one of the weirdos who thinks the game needs more XP/time sinks to keep the power level down) and helps thematically. However mechanically that makes it even weaker and I'd suggest that Spell Foci gains the flat +3 also if the ability is limited to one set of materials based on your chosen craft skill. Woodworking, leather working, weaving, all spring to mind. Metalwork is probably too broad and needs to be broken out into more specific skills due to the importance of some metals and shapes (but the game already supports that due to the importance of weapons and iron). Bookbinding and jewelry making (including gems) both look good. Cook or brewing would be hard to use as there aren't that many listed material things but I love the idea. Horn/ivory/bone might be a good one.
What am I missing or misunderstanding? No one seems to mention this virtue at all yet it is a Hermetic virtue written as it is has been generally incorporated into Hermetic theory. Is it just because as written it is fairly weak and the general thought around here is to focus on the more efficient use of V&F points? Would a spell created to use a spell foci double up on the bonus if you cast it using a talisman that incorporates that bonus?
I get the impression this was thrown in for people who liked the flavour of spell foci from 4th edition. I like it primarily for flavour reasons, but I don't think it's especially weak given how broad its effects can be
Slight clarification on Potent Magic: the +3 bonus is separate from Potent Spells, and not included into the Potent Spell itself. The wizard gains the bonus on any casting total or lab total covered by the focus and can make Potent Spells covered by the focus.
My Verditius has Minor Potent Magic (glass & clear gems). He gets a +3 casting/lab total on spells related to glass & clear gems -- like The Crystal Dart, or other spells he might create (turn enemy armor into glass, etc.) He can also make a Potent version of The Crystal Dart like the example in TMRE (p32) which has a +6 Potency bonus from using a dagger (+2) & spade (+4). My wizard would also add his +3 bonus to that +6 Potency (total = +9) for his casting total, but anyone else using his Potent spell only gets the +6.
Note that he's not using glass or clear gems to get the Potency bonus on that spell, and he gets his own +3 bonus regardless of whether he's incorporating glass or clear gems into his casting. Potent Magic doesn't "add one bonus from the shape and materials table to the CT when that spell is used."
I did not realize that the +3 and the Potency bonus were separated in that way. I also heavily and somewhat inaccurately summarized Potent Magic but that was more intentional as I figured most people would know it while Spell Foci seems to be much less well known.
Before you invest more time into developing a full set of house rules for magical components uses, what are you trying to achieve that the current rules prevent you to do ?
For example, if the purpose of material component is to provide a +3 to +5 bonus to spell casting, it won't matter in most case: sooner or later, the mage will have Arts good enough to neglect them. If Penetration matter, gaining AC and higher Penetration have usually a higher impact. There will always be corner cases where the +3 bonus matter, but it will be limited. Maybe don't spend too much time design rules for such niche cases. Also, Ars Magica tends to be quite crunchy with already many variables to add for casting, adding more might not be so fun to track.
However, if material components allow to have unique benefits, then, they can become very interesting. Some suggestions:
they allow to extend range/duration/target without needing a new spell
they allow to have access to mastery level for one casting
they allow to bypass requisit
while ceremonially cast, they grant effect similar to Watching Ward or Maintaining the Demanding Spell
Once you have selected the effect(s) material components grants, check what needs to be done to balance the effect:
is each component attune to a mage and works only for him, thus need to be researched individually by each mage ? Or is it a trade secret hard to find (maybe requiring experiment and Discovery success) and that can be traded for virtus or favours ?
are the components consumed ? How easy are they to come by ?
does it requires a specific skill limiting the effect of the component ? Is it Magic Theory or is it another one (Philosophae ? Medicine ?) or a unique skill ?
can they stack ?
do the use of material component strain the mage, making him get Long-term fatigue level for this increased benefit ?
The time I have spent was looking at the rules as written concerning the existing Spell Foci virtue and thinking at my keyboard about it. Note that the only development I did was wondering if a Hemetic mage could or should use craft magic. This is completely unneeded because RAW says they can simple use MT.
I'm afraid that our thoughts on roleplaying seem to be completely at odds.
Picking Spell Foci is an inefficient use of virtue points. Clearly. So are most of the virtues. I'm sure there are a couple of optimal meta build running around with the maximized power plus a plan that says exactly how to maximize your efficiency as you age the mage. None of that is particularly interesting to me. I'd rather create mages that are mechanically inefficient but also have mechanics that represent their individual strengths and weaknesses as closely as possible.
A kind of lateral move is considering leaning into Ceremonial Casting and specifically the expanded rules for Ceremonial objects, described in the Societates book starting at the bottom of page 58.
Its one of those expanded rules that you need a lot of ST awareness and possibly some troupe rulings around. My personal troupe ruling is that +1 and +5 bonuses can be simply crafted by craftsman with a minimum ability of 5, the objects with bonuses inbetween are objects gained by adventure.
I like them because they satisfy a certain amount of flexibility and flavor of a type of magic that I think you are persuing, with the benefit of it not needing a specific virtue and available for other players in the saga who can also pursue their own flavor of ceremonial items.
Yes. In fact I wonder if that is what the design was sort of meant to be - anything using more than voice and gestures is Ceremonial Casting and if you want to do it in normal speed then create charged items.
It works mostly. It does add an extra time element. You can't use it to create a better ward against fire on the spot because you are wearing a robe with small red gems sewn in (I'm not going to open the shape and material bonus table right now for the example) but you could take time and cast it.
Which, as @Ezechiel3571 points out might even be very efficient because soon enough you will be able to spont many spells so you might well be able to make good use of ceremonial magic + spont and not worry too much about mid level formulaic spell casting when time matters.
I really don't want to play the accounting mini-game, Ars is complicated enough as it is. If you specifically and deliberately sought out the Potent Magic virtue and intend to invent spells using various items, great, Ars allows you that freedom. But I don't want to track the contents of the pockets for every magus. Include the items in your talisman and move on.
It wouldn't be my favorite ruling for a saga but I respect that answer.
I'm old school enough to not mind some fiddling around with encumbrance and lists of things carried with the attendant possibility of loss at the worst moments.
If you're a Verditius you need to use casting tools, so depending on what your casting tool theme is you might already be using the equivalent tools you'd use for Potent Magic. If you have to do the bookkeeping anyway...
Edit to add -
The problem, at least for me, is that Verditius magic is a flaw. It requires casting tools all the time to allow the mage to use magic. For better or worse that is not the effect that I want