I was thinking about teleportation in Ars and its limits.
Leap of the Homecoming teleports you directly to a location to which you hold an arcane connection.
Now is there any way to stop this? Aside from an Aegis of course.
Even low level versions can be used to teleport through locked doors, wards, walls etc. And these can be cast very easily.
How would one go about setting up a ward versus teleportation? And would a magus be able to teleport across the boundary of a ReCo ward designed to stop humans? (assuming the ward has enough penetration to stop him walking across).
Teleportation, as a few other spells*, suffer from a lesser insonsistency that they only need to penetrate where/when they are cast. From then on the magic is stable regardless of most any other variable (foregoing Vim-spells). So to enable a solid way to limit teleportation one pf the steps would be to HR that casting a teleportation spells is both influenced by circumstances at the caster and/or target as well as in the other end of the spell.
A similar thing that has annoyed me slightly - that you could make all kinds of spell effects (or high penetration) while without the cathedral and then rush in without the local Aura, or Regio, influence it the least. I like the idea that the world makes you do certain things rather than others (such as doing your magic prior to entering), but I'd still like a minor effect of entering that Aura. Which I often do, but in descriptions only.
I think we could easily agree that it ought not be a matter of fact to do so - but the Teleportation rules are vague in this matter with the high levels ones not being moved from one place to another as much as not covering any distance in between. Coupled with the general Ward-challenges, these things aren't clearly adressed in the RAW.
I second that.
My only point is that it is HR and/or clarifying the RAW, and that it is needed. But those considerations would have to be made both before designing any spells and with universal considerations in mind.
As always there are several ways to get around being confined to one form. If vim isn't your strong point use corpus and a ward vs mundanes with high penetration to account for parma. Will need to be a higher level but you use what you can.
Ok, so clearly there is a gap, or at least something not considered in the RAW.
I recommend this as a houserule. Please feel free to let me know if i'm being dense and missing something important.
Under the rego Vim guidelines add this line
level 15 - prevent an object from entering this area via teleportation. A form requisite is required.
Therefore you could create
ward vs teleporting burglars
ReVim(Co) 30
Stops corpus based targets entering the warded circle via teleportation effects.
(Base 15, +1 touch, +2 ring, +0 circle)
This matches the level of the spell required to ward away normal humans (and magi) and should therefore be exactly as hard as stopping a magi from walking across your ward vs mundanes ward.
Or you could simply rule that mystically, teleporting out of/into a warded circle entails crossing it, no matter that your physical body technically doesn't. So you'd encounter both ReCo and PeVi wards that might be present. That would be my simple house rule for that case.