do immortals keep powers from other realms

No doubt. It's basically just a tool to make Vis more valuable, fighting more expensive and magi less inclined to help people.

Well, I'm sure they could. And the game would still be Ars Magica.

But I can't quite see why this limit is harder to believe in than the other. The limit of creation is just as strange, and limit of the lunar sphere feels almost absurd. It is true that "no vis-free instant healing" should get a lesser limit of its own, or perhaps become integrated in the limit of energy or creation. To me all the limits are obviously there only for game-balancing reasons.

Is it the limit as such or the fact that it doesn't have a proper lesser limit that you find so frustrating?

// Fredrik Hertzberg

The former. Apart from the OOC game style reason I told above, it's the only one limit (along with Limit of energy and creation) where my Middle Age paradigm and "hermetic theory makes sense" suspension of disbelief totally comes apart and I see the developer waggling a finger at me.
Arcane Connections, Infernal, Soul, Time, True Feeling, and Warping all make sense to me in terms of the overall philosophy of hermetic theory. Aging and Vis don't, but then mysteries have provided with effective loopholes around them, proving it was just flaws in the theory. Lunar Sphere looks bizarre, but then it is so unconsequential to gameplay that I chlk it under quaint setting detail. As for creation, it is quite annoying, because I can't reconcile it with the overall philosophy of the theory, but with an extreme, painful effort I can (barely) swallow it, since the game blance concerns behind it seem much more pressing to me than for insta-healing. Same thing with energyies. But healing it is not creation nor energy; it is repairing. A wholly different beast.

Moreover, I've played several other good magic systems, and they generally share the same game balance concerns about pulling out stuff from nothing and renewing the same kind of energy one uses to power magic. But no one puts such an absolute limit to healing. They all do "you have to keep meditating on X minutes to fix the spell" or " you can only heal X amount of damage per day" and in my experience they settle the insta-healing problem much better than the ArM solution (which I deem the only big lingering flaw of an otherwise most beautiful system). IMO it is but an ugly legacy of the time ArM first-edition badly over-reacted to D&D faults.

I think I understand what you are trying to say much better now. And I agree that they have chosen to use very heavy-handed mechanics to deal with a relatively minor issue.

In an attempt to become a bit more constructive, let's look at the advantages of the current system as well as the possible alternatives.

These are the good properties of the current system, as far as I can see.
*Slow healing means that wounds are significant
*Requiring vis makes vis more valuable
*Requiring rituals makes rituals more usefull for adventurers
*Requiring rituals means no weird healing magic items
*The system is very much in line with the limitations placed on creation
*The system is very simple and not prone to missunderstandings

Any real alternatives should be able to match that list some way or another.

These are all the possible limitations I could think of right now.
*Healing uses resources
*healing requires time
*healing doesn't work very well
*healing damages the healer somehow
*healing damages the healed somehow (warping...)
*healing has a definite limit per period of time
*the healed is never grateful (difficult to explain why though)
*only a specific group can be healed, like relatives
*healing brings poor supernatural relations
*healing only works in very specific circumstances
*healing is extemely painfull

How does all this look from you point of view? I am still not 100% certain that an alternative would really be better, all things considered. But I am ready to give it a shot, for you are completely right in your observation that healing is nowhere near as dangerous as creation.

// Fredrik Hertzberg

With the use of Momentary CrCO Rituals to increase stats permanently ,
(this also does not cause warping)
I wondered if it was possible to give someone a permanent Recovery Roll boost.
All stats can be increased to +05 , and this is considered Natural.
(i know that the only practical drawback is Vis availabilty)
So i figured that a Momentary Duration CrCo Ritual (using Vis) could give a permanent Recovery Roll bonus.
( At maximum it would be +18 )
This is a Level 20 effect (Base 15 , +01 Touch)

David Chart did give me an answer as to why this wasn't the case ,
but i can no longer find his reply.