I was having a conversation about magic items and we came to an interesting question. In my games, I've never had hermetic wizards assign levels of penetration to items intended to target the wearer- like rings that make you invisible or protective warding jewelry.
So, my question is, do items that are intended to have such effects require penetration to affect Hermetic Magi (who by nature will always have magic resistance)? Are Magi intended to suppress or drop their parma to allow, for example, continuous magical items to affect them?
Yes, such items need to penetrate the Magic Resistance of whoever they try to affect.
All spells and effects need to penetrate the MR (if any) of their target to have any effect - the exception being if they have Range:Personal.
So if a mage wants to be affected by an item he will need to suppress his MR for a few moments.
A ring that makes you invisible and a ring that incinerates its wearer follow the same rules - and anyone being unlucky enough to put on the second type of ring will be very happy if their MR protects them.
What I'm really interested in knowing, though, is if that's the intention around which the game's magic item rules were designed. If all magic item present in the book are designed around this expectation and if this is intended to have the impressive impact it would have on Hermetic Society.
For a definitive answer about the intention you will have to ask the authors and hope they remember, but I feel fairly confident in stating that yes, the magic item rules work as intended.
I suspect it is not uncommon for people to forget that items generally need to penetrate, so some of the items you can find in books other than the core rule book may not have been designed with that in mind.
Eh, for an invisibility ring it's not particularly farfetched that a magus could suppress his MR momentarily when he puts the ring on, before he goes sneaking. Likewise for e.g. Aura of Ennobled Presence before entering a social scene.
On the other hand, for e.g. a Gift of the Bear's Fortitude item, or similar defensive buffs (possibly including invisibility!) is the sort of thing he'll want to trigger immediately on being attacked, without suppressing his Parma, and so will really want some extra Penetration built into the enchantment, unless it's in his talisman.
I am not fully convinced. It feels like it could break the classic Verditius concept, of a magus who rely primarily on items and rarely cast spells, particularly the rings for every finger.
Now, suppressing PM for an instant to put the ring on is not that big a deal, but how does this work with constant effects where the device maintains concentration? I am not sure if RAW answers this, but intuitively, to me, that maintained concentration has to penetrate continuously. Does anyone know?
For other magi, less biased than the Verditius, this has an interesting consequence. Suddenly talismans become more powerful and interesting, by allowing Per range effects. Having a number of lesser enchanted devices to affect oneself becomes less attractive. That may very well be a good thing.
For items which affect other people it won't make any difference - there it should be obvious that the effect will have to penetrate any MR.
Keep in mind though that normal spells also need to penetrate unless they have Range:Personal.
This includes R:Touch spells cast by the magus on himself.
For effects with D:Conc I see no need for continous penetration, any more than a normal spell with D:Conc need to penetrate more than once.
For typical constant effects (D:Sun, Enviromental trigger to refresh the spell at sunrise/sunset) one could argue that the wearer would have to drop MR when the effect is refreshed, but this is not quite clear.
Talismans have many advantages over other enchanted items, and this is a major one indeed.
I, on the other hand, would argue that when ArM5 says "Such a device has a truly constant effect; there are no “flickers” at sunrise or sunset." it means exactly that, and thus suppressing your MR momentarily to put on a constant-effect item lets you continue benefit from its effects for as many days or years as you leave it on for.
I believe this has been addressed, in terms of how often a MuVi spell needs to affect such a constant effect in a device. The answer is twice/day, so the "official" interpretation is that the effect is recast twice daily. Check out "Anointing of the King" in the errata. It came in the aftermath of a rather intense discussion, where the pros and cons of both interpretations where evaluated.
It rarely matters for ordinary spells, since concentration is limited. Items OTOH have unlimited concentration.
How I think of it is that casting a spell of any other duration, the caster applies all the power at once, and once it is past the MR, it keeps burning. Concentration duration OTOH means that the caster is constantly supplying more energy to the effect. How does that energy get through the MR?
Yes, that is correct. It used to fire off one time and last forever. That was how Anointing the King was handled and deemed correct. But later David Chart changed how "constant" behaves. So now it really isn't constant; it's separate back-to-back effects that leave no gap.
Actually, Hermetic items lose concentration at sunrise/sunset. You can maintain the concentration yourself through then to keep the effect going, though. Outside of that sunrise/sunset issue items have essentially unlimited concentration, yes.
That's like asking why Sun spells don't have to keep bypassing MR because the sun keeps supplying more energy if you travel westward.