I was thinking about possible flaws for my magus. One of the things that I always liked is imperfect Gifts and abilities, that render ceertain areas weaker than others., Incompatible arts, weak parma, weak forms.... puissant forms... all those have always made me think about a richer Gift layout than a pure, perfect gift with only strengths in it.
One of the weaknesses in my Gift I am likely to incorporate is a weak MR.
I thought about the option about this being KNOWN by some people. Not necessarily known bny everyone, but by some people at least. That makes for an interesting flaw in my character.
That should count as a flaw IMO. The point is how many people should know it and in what terms should I be with them in order for it to be a minor flaw.
The story would be about a fellow apprentice that used to cast smallish terram spells at me while I casted ice spells at him during our apprenticeship (you know how teenagers can be. Both apoprentices being protected by their master's Parma and unable to boost much penetration, the effects of such spells were negligible.
Now, after graduation and being taught parma the other apprentice would salute me casting a forceless (and careless) crystal dart at me just to annoy me.... and causing quite a wound!
Now, that could easily be determined to be a glitch in my parma by any onlooker. I pretend to be on OK terms with the other ex-apprentice but not being a friend of mine either. Just a class companion so to speak.
Such an event could easily have happened in a covenant my magus was visiting to get further training or to peer into a certain book. So it is bound to be onlookers that are not bound to my magus by any specific loyalty factors, both magi and covenfolk.
So, in your opinion how many magi should in your opinion know about it to become a flaw?
Very difficult question indeed...
I think it depends on WHO it is that knows it.
If its some scheeming antagonistic archrival knowing it, id possibly outright make it a major flaw, if its "just" 10-20 magi that are "neutral" or even friendly and not terribly bigmouthed it just barely qualifies as a minor.
Want a number, lets say 5-10 if it includes at least someone that dislikes you and is close enough at hand that you will have to deal with s/he sometimes.
The flaw is enough in itself, following my opinion.
And there's only one person who should know this: your parens. I don't see any reason for other people to know your weakness (unless you took flaws that makes your parens dislike you)
Well, the character does have the flaw weak magic resistance. On top of that, I want to have ANOTHER flaw. This is why I was asking It is not the Weak MR flaw itself, but a second flaw. More clear, now?
Weak MR basically makes you suffer from 4th edition penetration rules under the mentioned circumstances. So with a parma of 1 and ignem say 4 (just finished apprenticeship) you would be hit squarely in the forehead by a level 10 CrIg spell casted forcelessly (casting total of 10 = penetration of 10 even casting forcelessly). I like this magical "accident" creating a weakness in my character's armor.
As far as flaws go I would consider it a notable one, especially since it could also be applied in your Magus' routine dealings with other magi (especially sodales). With a weak MR (read Parma I guess) he/she would be susceptible to the negative effects of the Gift in other magi and likely be extremely distrusting of all other members of the Orders as would any mundane.
Another thought instead (if such a repercussion seems incompatible with the path your character intends to pursue) then why not instead translate Weake MR into deficient form score resistance and say that he/she simply derives only half the benefit of any form as added resistance to his/her otherwise normal Parma? Or perhaps better yet, Deficiency in all but ONE form resistance bonus and in that ONE he/she has no benefit in terms of added resistance bonus altogether?
I might even be inclined to argue that such a flaw would be minor so long as the Parma itself was fairly high.
It should matter (for backstory purposes) precisely who does know about this weakness, however it is finally drawn up.
{edited to add: sorry didnt read your clarification directly above before I posted. So just think about what I have suggested as the added debilitation that you are seeking.}
One of the things is that I do not want to know who knows about it.
It makes for a much more interesting flaw if I am not fully aware of who knows of my weakness. A pair of the winesses for sure, but maybe they talked....
I do not intend my character to have enemies as a flaw: having enemies that know about this would make it major IMO. No, it is more a thing that might come around from time to time.
I ended up selecting "near large fires" as the weakness. That includes Ignem spells doing +15 damage or above, so quite a common occurrence. A POF can undo me easily if caught off guard. it is an extremely common form for offensive spells, so I'd better not enter too many WWs regardless of my killing prowess.
Not knowing who knows about the flaw will make my character a little bit edgy, and likely to carry antifire defences around most of the time just in case. besides, it will make the SG laugh maniatically each time he introduces a new Flambeau into the saga
3 confirmed withnesses (and add to that my Parens) and a 1D10 extra magi that know about it might be a good number of people knowing about it you think? I will leave it to mark Faulkner make the roll.
This can easily enter a political discussion as well: suggesting that the tale might be spread can be a way of blackmailing my character, after all.
I would still say that your character's Weak MR will leave him distrustful of other magi regardless of any possible knowledge of his weaknesses. This will make for an interesting if somewhat paranoid character.
Just remember: Even though he's paranoid doesn't mean THEY are not out to get him!
He prefers the solitude of the wilds for some reason, after all. Not directly averse to social interaction, but wary of it.
However, as I have repreatedly said in other threads, hermetic magic resistance is a pure joke regarding other hermetic mages. An hermetic mage can kill you in a blink of an eye without even specializing a lot about it. Thwe wonders of Parma are in reducing the social penalty, not in providing a fool proof defence vs other magi. Being weaker in defence does not place my mage* that* far behind in that sense.
It's the social penalties of the Gift to which I was referring, not so much the question of defense from attack spells. Seems to me that Weak MR for a magus translates to weak Parma and thus to an increased social penalty for your magus when interacting with other magi.
If it's the wilds you seek out more often than not then don't be surprised if you have frequent dealings with my character
The social penalty does not depend on glitches in your parma at all, or the level of your parma for that matter. As long aas you have an active parma it is enough to reduce the penalties to 0.
So no, that is not a real issue here.
If I have to interact with you a lot, I hope you are not an ignem fanatic, then. LMAO
That alone could be argued as enough to make the flaw Major, because as you said its going to be nasty to have to keep a lookout all the time just in case.
2D6 instead of 1D10 perhaps? Otherwise a very low roll might make the number of unknowns just 1 or 2 and that might counteract the "unknown" element you wanted.
Yeah, basically that either LOTS of people know about it(if dozens of people knows it, you can probably expect many to talk much too widely about it regardless if intentionally or not) or that people clearly potentially hostile(or simply outright enemies) to you knows it.
It is not the Weak MR flaw itself, but a second flaw. More clear, now? 
