It's correct. In fact, you can use much lower level effects to obtain what you are looking for: any spell affecting a target, makes that target "blockable" by magic resistance (including parma). Including an effect making the target sprout a pink dot, hence the very name "pink dot effect" that you'll encounter on this forum for this issue. Lots of people think it's a serious loophole in the current rules, that troupes should just agree not to exploit. A few, like me, think it's really ok. Almost everyone agrees that any attempt to change how magic resistance works so as to fix it will create other problems at least as serious.
Ok. This point must have been discussed at length. Sure, magical resistance is not something to change without care. I won't even try to do it
I just find it's a bit annoying that magi can become nearly invulnerable to all mundane attacks at such a low cost. Of course, they are vulnerable to magic and other supernatural attacks, but this is still powerful.
That's true... to a point.
First of all, note that attacks that block/constrict/entangle/blind won't do direct damage if "pink dotted", but can still impede movement and/or sight.
Second, you can't in general "pink dot" an attack you are not aware of; the stereotypical "dagger in the back" (if mundane) strikes with full force. As does any mundane attack that's faster than your "pink dot" spell.
Also at some point you can simply be overwhelmed trying to cast pink dots against every attack. For example, if you pink dot an arrow the next arrow is free of dots (unless you dot the group in the quiver...), and are spending your time casting dots instead of other defenses or retaliatory actions.
As I read the rules on Parma Magica and Magic Resistance, PM protects you from magical effects, not mundane ones.
Example: Magus is attacked by a knight. The magus sets the knight's sword on fire. The knight strikes the magus with the flaming sword. Presuming the magus does not penetrate his own parma, the flame does the magus no harm - but the sword does.
So; you cast Phantom Gift on a mundane attacking you, witnessed by other mundanes. He now seems as a magus to other mundanes. Parma blocks this effect (and affect), so to the magus he seems just the same as ever. The mundane then beats the magus to death with his fists, and is looked on askance and with considerable suspicion by his fellows until the spell ends.
Considering they hold him in great suspicion, the mundane may be held a murderer, rather than a hero defending against a creepy magus.
TimOB, but that is precisely the issue: any solution gives place to another issue.
For example from your reading, we could have a magus decide to use a ReFo spell to move an object (rego penetrating style) then saying "ok you say this for a flame sword. I move the arrow magically, but I only use my magic on the quill, not on the metallic head, so it doesn't need to penetrate". (For the record, in our group IRL we use that kind of parma magica rule you explain, so I'm not saying it is trash ^^ just that it opens a new can of issues.)
I agree with a previous poster: any troupe/saga rule is fine, with the SG having the final word and a general "if that feels like an exploit of the rule, just agree to not use it". It's way more interesting and playable. When players stop considering flaws in a game mechanic, the game is more playable.
(Remains the fact that sometimes, something is considered game exploit by one, and not by another... SG decision again always is final.)
My initial point was not to "pink dot" attacks (I love the term ), but a whole bunch of nearby objects. However, you are true that the dagger used to backstab such a magus could have been concealed in the beginning of the spell and then still mundane.
This is certainly the best answer a troupe can give to such problems
The usual example of pink dot is as corollary to edge of the Razor- where the item has been altered by magic. An object propelled by magic needs to penetrate parma- an object propelled by magic and released (requiring a inesse roll to hit) does not. Magically created water needs to penetrate parma to get a mage wet, magically propelled water does not, though the force of the propulsion needs to penetrate to affect the magus.
In theory I suppose you could use this to propel embers or burning material towards the magus and try to burn them without engaging their parma...