Has anyone attempted to use this in their saga and, if so, what was your experience? Any unexpected side-effects of this change?
I'd love to benefit from your advice as I consider trying it out.
I think there should be a sticky post on this topic, it's comes up from time to time. Alas, I can't find my old thread where I asked the same question. I'll keep looking...
I considered doing this, but gave it up because it doesn't work well for some certain arts. If you're looking for a low powered saga, it works well for the elemental arts but it makes most Mentem and a few other notable effects out of reach.
Edit: Found it [url]https://forum.atlas-games.com/t/hermetic-arts-as-difficult-arts/5104/1]
A much simpler way to achieve this goal is to halve the Lab Total and the limit for the highest spell level during character generation.
Less work, no balancing problems and the higher level formulaic spells have a good penetration since their Casting Total (which is not divided by 2) is automatically much higher than the spell level.
Make some use of it to make characters with less than normal/standard quality Gift. Dont like it as an overall change.
That messes things up severely...
For that kind of change, take the table on top left p81 AM5 and modify either or both of what is needed to cast a spell and how much fatigue is caused and at what level.
I did it in a three year saga before Ars Magica 5th Ed came out.
It worked really well. I thoroughly recommend it if you want to tone down the power level of wizards while still allowing the full range of magical effects for older magi. Also, modifiers become much more important, which means magic becomes more "flavoursome" as players try to get every last newts eye and ruby ring.
And this is where I think MdV nailed it.
Cheers,
Xavi
Sorry Xavi, but I didn't see this one on the list of abbreviations. What's MdV?
Michael de Verteuil. The author of the Heretic's Corner articles. 
Co-author of Ordo Nobilis as well.
Xavi
I don't see any problems.
The casting total is not(!) changed.
Or is a standard mage unbalanced, who limits himself to formulaic/ritual spells with a level not greater than half of his lab total?
The advantage of formulaic spells over fatiguing spontaneous magic is the "build-in" penetration.
Higher level spells have more "build-in" penetration, this gives a certain 4th edition feeling.
And fatiguing formulaic/ritual spells got out of style with the new penetration rules in 5th edition. At least in the campaigns I gamemastered/played. It was a viable option in second to fourth edition for high level spells.
I have always thought it un-classy that a character with CrTe 5 or so can cast Conjuring the mystic tower without much problems using a casting tablet. 
So what? If you make a +10 change to the table mentioned, you must have at least the level of the spell in casting total for it to be cast instead of being able to cast it with up to 10 below spell level.
Formulaic spells already use the full casting total, so why give an extra 10 as a freebie?
You then set up a situation where Formulaic are barely any better than Spontaneous. Halved lab total means the only real difference is the extra penetration, so except for combat spells or similar that needs penetration, why should you bother learning any Formulaic spells at all?
Halved lab total also means learning time double or worse. And then, do you expect to keep running with halved lab total for everything? In that case, item making becomes very difficult and time consuming.
If not, then you just made item makers potentially insanely powerful.
Just :
- don't using casting tablet
- or use them as texts for learned magicians: casting total is casting score/5, with a stress die (but only for botch purpose (as with unpredictable magic and a non fatiguing spontaneous spell)).
It helps.
Personally, I don't use casting tablets much. The fact that rituals are always stressful, if not in calm and mastered (which is impossible with casting), is too risky. And I would double the botch dice in case of tablets. After all, it's not a safe way of doing magic.
learning low level hermetics is REALLU useful for when you are casting in negative auras. There your casting total HALVES might still reach the spell level of a formulaic, so you can cast it without fatigue. Your spont magic would simply not reach that level, fatigue you and generally, suck big time.
Not everything is penetration when God or Satan decide to screw you.
Xavi
If you have Arts as Abilities , do you keep Diedne Magic as a Major Hermetic Virtue and Magical Foci?
I agree and don't use casting tablets. Magi advance quickly enough that they don't need to get the use of all the basic home spells like Aegis of the Hearth without spending seasons learning them.
It's an area that could stand more emphasis in the game with or without Arts as Abilities. Right now there's no benefit to creating spells in an atmospheric way, with the result that most player created magic is less interesting than the legacy spells in the core book.
I strongly disagree...
It depends of your player. My players have the habit to describe their spells in colorful ways... and when they experiment, the description becomes really a piece of art since it encompasses the various "side effects" (good, bad and neutral) ^^.
Besides, your sigil is a part of the spell. THus, it has to be contained. But for that part, most players just forget, and it's the SG who has to play it and change the description of spell to include it.
I pretty much said what I had to on the other thread. On the few sessions I used it in, I found that I really liked the way it bolstered up all those little bonuses and rewarded creativity. However, I never implemented it in a long-run saga. It has been pointed out to me that it discourages specialization.
Of course, I didn't reduce the spell-levels, I only changed the cost of increasing Arts. I'm not sure if that's what being referred to.
And of course, if you change Arts to progress as Abilities you'd probably want to change a few other minor rules to suit them. Like the number of tractatus that can be written, that sort of thing.
Yair
I think you have to align all these little points of rules on the corresponding ability ones.