Any magus can be tried for anything at all, by any Tribunal anywhere, if the case is brought by someone before that Tribunal. A successful defense is simply anything at all that deters the case from being made, denies the bringer of the case the support of a majority vote, or convinces the Presiding Quaesitor to issue a veto. Sometimes that'll be a fine parsing of the Peripheral Code, sure, but it doesn't have to be.
The question in the case of a theoretical vagrancy case made against a covenant in Mythic Abkhazia is never "Can someone parse the Code to bring a case that's technically correct?" but always "Would anyone bother making the case, and would a majority of voters at the Tribunal think it a good idea to vote to convict?"
If someone does bring the vagrancy case before the (say) Levant Tribunal, the Levant's voters are going to ask themselves questions like, "All right, let's say we vote to convict the Mythic Abkhazians of vagrancy. Is it really more likely that we're going to get something from them we want as a result, or that instead they send us a snide note explaining that they've always been a Novgorod covenant and thank you for reminding them to formally register that with the Redcaps? And in the latter case, would it be worth pursuing to the Grand Tribunal, or would we just let the precedent that Abkhazia is part of Novgorod stand? Isn't the prudent move here to leave them alone until they decide they need the protection of a Tribunal?"
If a maga brings a case against you in the Levant Tribunal, the Levant Tribunal votes to convict you, and the Levant's Presiding Quaesitor refrains from using his veto, it doesn't really matter in the slightest how much the Peripheral Code says you, a magus who has never set foot outside of Wales, were not in the Levant Tribunal's jurisdiction.
Now, sure, a clear statement in the Peripheral Code hopefully will convince the maga not to bring her case in the Levant, it probably will convince the Levant not to vote to convict you, and it almost certainly will convince the Levant's Presiding Quaesitor to veto the verdict if it gets that far.
But if it doesn't convince them, you don't get as much as a +1 "wrong jurisdiction" bonus to your Magic Resistance against the spells of a hoplite from the Levant trying to take your Marched head in an ambush.
What you say, @SEE , holds for any charge, illegal or legal, and in particular, the hoplite would have as little protection as you have, if the other tribunal decides to make a case against them.
From memory, a Maga once petitioned the Rhine Tribunal to rule on a case in Stonehenge Tribunal, because Stonehenge had been inquorate for so long.
the Rhine Tribunal ruled it had no jurisdiction outside it's borders.
this might just be a local Peripheral Code ruling, but it is precedent to call upon.
I suspect this is in the Guernicus chapter of HoH:TL
Tribunals are not strictly territorial; they are memberships. There are covenants that set up in the nominal area of one Tribunal, but attend another (lone magi, too). Territoriality is a function of locality, common or associated culture, and relative ease of travel.
A covenant that sets up shop in an unclaimed area might petition to be recognized by one Tribunal. If accepted, no trouble.
If rejected, they can petition another convenient Tribunal. If there is no other Tribunal, problem (which means, politics and plots).
If all Tribunals reject them, see previous answer.
If rejected by all available Tribunals, I'm a little curious who is going to prosecute them? How do the Quaesitors determine jurisdiction? Can lack of Tribunal membership due to rejection be used to disband a covenant?
It's possible there may be another few covenants with similar situations relatively nearby. Perhaps they would then organize a Tribunal, although this goes back to the unanswered question of how a new Tribunal is accepted by the Order/Grand Tribunal. Fiat?
Of course, maybe the covenant does not want to be in a Tribunal, which means little interference, but also little support. If the covenant is remote and inoffensive, no problem. If they start stirring trouble, problem.
Tribunals are strictly territorial, in the sense that if you set up a covenant in the territory claimed by Normandy, Rhine, or the Greater Alps (the latter assuming 4ed canon). and seek membership in another tribunal, they will prosecute you for breaking the peripheral code which in those tribunals is rigged to control population and manage resources. The borders may not be strict, but the territoriality is.
Setting up a new tribunal requires four covenants and twelve magi, so if you are talking one covenant, it is not on the table.
Now, covenants do not swear the Oath, only magi are legal persons responsible to the Code. Hence, covenants cannot be prosecuted. and a covenant may exist beyond the Code and beyond every tribunal, but the member magi have to be formally resident in a tribunal and abide by their Peripheral Code. In addition, they have to abide by the Peripheral Code in any tribunal with the will and power to claim the area.
Weirdly, this makes me think of the Hutt River Principality.
According to one of the background stories I read years ago, when the local Australian government failed to heed his petition about wheat quotas, the farmer invoked some old English law (and Australia had effectively inherited English law unless explicitly legislated against) that said (paraphrasing from poor memory) if your local fiefdom failed to uphold the oaths of Fealty you could move to a neighbouring fiefdom. But since there was no neighboring fiefdom on the continent of Australia, he effectively left Australia the country and became an independent state.
I understand the Australian Parliament would later legislate this clause away, and tried to act as if it was retroactive.
Law is only as good as the will to prosecute it. How much does the tribunal care?There's a bunch of precedents, peripheral rulings, etc, however, if a magi has annoyed enough people, unless the SG decides there is a Quaesitor or very significant magi who is a stickler for the rules, those precendents will mean nothing. And by the same token, if there is a beloved magi, or one who has a lot of favours owed, they may well get away with things they should not.
Also, another thing to remember in AM that is completely different to modern day law. A magi can just say "This magi deserves to die, I will kill him next month", and it is accepted as an option. As Flambeau wanted, that will always keep the lawyers on their toes and not over-reaching.
Nidi in Normandy/Provence, Roznov in Rhine/Transylvania, Evredika and/or Gigas in Transylvania/Thebes, and Spider's Palace, Florum, and Triamore in Rhine/Normandy all intrude on strictly geographic territoriality, plus the edge case of Fengheld House in France. The Transylvania locations are nominally not covenants; covenants are associations, not places in Transylvania.
Tribunals are not strictly territorial, any more than mundane kingdoms are. They're a medieval muddle; part geographically territorial, part historical, part agreement, part tradition, part mystery.