Most of the original members of House ex Miscellanea would have been mostly non-Hermetic in their magics. Some in the 13th Century might still be like that. But I am wondering about if other Houses in 13thC might have non-Hermetic magic users as full Magi?
Take a hypothetical Tytalus who takes an apprentice already opened in another Tradition. Gives the Apprentice's former master the option "either train the Apprentice under my direction, or die", while managing to open the Apprentice's Gift to Hermetic magic without losing the original Tradition.
Then has the apprentice trained in the original Tradition under exacting Tytalan standards. While also teaching H. magic Theory and such, but no Arts. And apprentice passes a sufficiently difficult (by Tytalus standards) Gauntlet using non-Hermetic Magic.
Is there anything in canon that would prevent this? (including Tytalus mindset)
Jerbiton: don't they have anymore the larta mage (artist, philosopher, ...)
Mercere: could be possible, they accept a not-hermetic caster as a redcap?
We had once a story of twins - one was a non-gifted twin, but killed in duty, the other a spirit master/summoner. the ghost of his dead brother ask the summoner, to take the role of the mercere, to find his murder ... later the house found out and accepted him as redcap, cause we was in the role a exceptional mercere and faithful with the order ...
It is perfectly possible to play a Hedge Wizard who was sworn in as a member of the Order, learned Parma, but chose to retain his original magic. Getting your Gift opened to Hermetic Magic is entirely optional.
There are no hard rules against it, but depending on your standing and the Tribunal you're in, someone might try to sue you for "depriving these Wizards of magical resources" by not opening their Gift to Hermetic Magic. Indeed accepting conversion would leave them severely weakened though I'm sure many will argue it's for the long-term benefit of the tradition.
There are a handful of Gruagachan in Loch Leglean that were recruited in such a manner; what info we have on them is mostly from previous editions, but Hedge Magic book at least confirms they are still canon.
Learned Magicians, should they ever be recruited, are also said to likely be keeping their own magic and thus be Hermtics only nominally.
Sure, both of these examples Hedgies would have the Parma, follow the Code and enjoy the full protection of Hermetic Law. One thing to consider is that keeping their OG magic means they cannot practice Certamen and so might need to be crafty about how they handle themselves at tribunal...or if they are sufficiently martial (and ballsy) just shoot such challenges down as abuse of the law and declare Wizard War instead.
To be fair, Flambeau do have 2 lineages from recruited non-latin Hedge Wizards. One in Normandy that comes from Rune Wizards, another in Hibernia from the local Druids (who just so happened to hate Diedne guts).
Look up the Lineage of Pralix in HoH:Societates (pp.126-129):
As well as this theoretical interest
in exotic magic, the Lineage of Pralix are
also interested in seeking out new magical
traditions and assisting their passage into
the Order through House Ex Miscellanea.
Such magi hate the idea of a tradition
of magic being lost forever, and they are
unusually adept at translating exotic magic
into its Hermetic equivalents. When a new
tradition enters House Ex Miscellanea, the
members of this lineage are often instrumental
in helping the hedge wizards to
train the second generation of pupils, and
encouraging the acceptance of Hermetic
magic while preserving the original magic.
In theory, any magus with a high-enough InVi can do this, but the Lineage of Pralix has an advantage because their Minor Magical Focus with Exotic Magic applies to such a situation.
Possibly. The basic qualification of Redcap is to be an agent of communication (letters, currency, trade, spying). Note that it is not an any-idiot job, though. I assume they go through a long apprenticeship training to gain the many many skills needed.
Actually, the original members of every House (other than, perhaps, Bonisagus) were non-Hermetic In fact, even after the founding, most Houses took in non-Hermetic Wizards. This is true even of True Lineages: for example, House Tremere took in Dacian Necromancers (HoH:TL p.112) and the Line of Muj (HoH:MC p.77).
The question can be read in several different ways.
Legally? Sure, why not. There is ample precedent, and all you need to do is swear the Oath and join a House (which must accept you, though). Socially? Hmm, by 1220 it would probably be seriously frowned upon. There seems to be a general feeling that, if you are not a "proper" Hermetic Wizard, you should at the very best allowed to join Ex Miscellanea, if at all. For example, House Tremere in Transylvania trains a large number of Gifted children in a non-Hermetic tradition, that of the Fectores, and then has them join House ex-Miscellanea (AtD p.43); even if they are allegedly "loyal to House Tremere rather than the Order of Hermes as a whole" (AtT p.44) - what would happen if House Miscellanea cast them out because of this, is anyone's guess. Canonically? Fully non-Hermetic ex-Miscellanea wizards are canonical even in 1220, and HoH:S p.107 has rules for creating them as PCs; but no such characters are mentioned in the books outside ex-Miscellanea as far as I know. On the other hand, nothing in the books says they do not exist, either, so...
No outsider should
But given that there is technically a Flaw for magical Mercere ("Illegitimate Lineage" - HoH:TL p.109) that specifically states "You were raised in House Mercere, but are not descended by blood from Mercere or one of his heirs, and so are not considered a “true" Mercere.", it is not strictly an impossibility.
"Illegitimate Lineage" doesn't make you an outsider as such.
You have still gone through an apprenticeship in House Mercere, even if you aren't descended from Mercere the founder and thus not a "proper" Mercere magus.
For all the True Lineage houses you must have been apprenticed to a mage of that house and passed tha gauntlet at the end of that apprenticeship.
A Bonisagus could, in theory, "bonisnatch" the apprentice of some none-hermetic magus in House Ex Miscellanea shortly before the end of their apprenticeship, and then graduate them as a magus Bonisagi.
In practice that would be extremely rare if it happens at all. Most Bonisagus magi are far too proud of hermetic magic to want an apprentice who aren't skilled at it.
Ex Miscellanea does occasionally accept non-hermetic magi into their house, and the other Society houses as well as the Mystery houses could as well if the applicant is deemed fitting for their house. Such would be rare though.
After the diabolic corruption scandal in House Tytalus, the Titanoi had only a handful of members left - most of them young and inexperienced. So they invited a bunch of Greek theurgists to join the House and help rebuild the Titanoi.
Just as an example of outsiders joining a house other than Ex Misc.
In the early days of the Order, before House Ex Miscellanea had come into being, houses Flambeau, Tytalus, and Diedne all recruited heavily among hedge wizards.
It seems our disagreement is only on what "outsider" meant
I had read it as someone "not of the blood of Mercere".
Also note that there is no standard definition of what "being apprenticed" has to involve. So, technically a non-Hermetic wizard could be "apprenticed" in House Mercere, remaining a non-Hermetic wizard, and becoming an (Illegitimate) member of House Mercere.
In fact, as Arthur mentions, in principle some random descendant of Mercere could manifest the Gift and get trained as a non-Hermetic wizard, only to be discovered later by the Mercere magi. Of all the Houses, they would probably the keenest to recruit such a magus (rather than having him enter ex-Miscellanea), after a short "apprenticeship" to teach him the ropes (including Parma).