I am designing an NPC magus specialized in Intangible Tunnels (basically the concept is some kind of gunslinger), and I started thinking about Tethered Magic. First of all, Intangible Tunnel's definition says that any spell with range greater than Personal can be cast through the tunnel (though that makes me feel odd with range: Eye. Despite being legal, it just seems wrong), but what if the caster have that virtue? Would you allow him to tether personal spells through the tunnel or stick to the stated range need? I just don't see why not. Usually it's obvious that a Personal range spell wouldn't be able to be tunneled, but if it's tethered then what reasons are there to disallow him of using Personal ranged spells tunneled?
Another concern I have is the Tethered Magic requirement of spells having a duration greater than momentary to affect the target. This could be reasoned because the caster needs time to cast the spell and then place it on the tethered target, maybe touching it or whatever (rules on how spells are tethered are quite vague on how tethering actually happens), but what if the caster is already touching the target? (or have it under an Intangible Tunnel connection, in my case) Would you allow momentary spells to be tethered then?
The downside my gunslinger would have is that through Intangible Tunnel already opens the possibility of spells being casted back to him, Tethered Magic makes spells arcane connections to the target, so it would be easier to strike him back, if only because spells casted through the tunnel will probably be easier to detect (after all it's easier to recognize that you are under the effect of a hostile spell when you burst in flames). Which makes me wonder one final question: when a magus is targeted by an intangible tunnel, it's stated that he can also cast spells through the tunnel, but to cast a spell you must fist be able to notice the target of your spell, so would the targeted magus need first an Intellego spell to find his attacker, or would you just allow him to cast spells down the tunnel, assuming "whatever is on the other side of this tunnel" is clear enough to be considered as an identified enough target?
Regarding Eye range for a tunnel: I agree that wording for the Intangible tunnel does indeed say "any range greater than Personal". However, I think this strongly implies "any range greater than Personal that is capable of targeting the local end of an intangible tunnel". So, Touch/Voice/Sight would be the main 3, as would any exotic (but still Hermetic) ranges that could actually affect the tunnel.
This is supported (unfortunately in the negative) by the expanded discussion of Intangible Tunnels in Hermetic Projects, on pg. 79. The bullet item which discusses ranges Only talks about Touch/Voice/Sight, and specifically doesn't talk about Eye or Arcane Connection. The second-to-last bullet point (on pg. 80) mentions the exotic ranges and the fact that they still could affect the tunnel.
However - I would also agree that this isn't a golden bullet in terms of evidence. Personally, I'd rule that you have to be able to target the tunnel in order to cast a spell through it. However, I can see someone taking a strict interpretation to the RAW ruling otherwise.
EDIT - that being said, I can totally seem someone whipping up a MuVi effect on an intangible tunnel that grants it an Eye that you can make contact with.
I would allow Range: Eye, as long as you are making eye contact with the person on the other end. Exactly as it says in the core book. If your eyes can't meet, then you can't do the spell. There is a definite distinction between seeing someone's eyes, and eyes meeting. They have to look back at you.
In most cases R:Eye is impractical for Intangible Tunnel, unless you have some type of magical effect that lets you see each other....
Hm. I think the issue I have with that interpretation is that it applies to all targets - you have to touch your target if you're using range: Touch, or see them if you are using range: Sight. So to be consistent with your interpretation, you'd have to be able to touch the target to cast a Touch-based spell through an Intangible tunnel, which defeats the whole point of the effect.
That being said, I fully agree that a Tunnel, as described in the core rulebook, doesn't have an Eye that looks back at you. So in that sense it can't be used - and everyone EXCEPT the person who cast it wouldn't be able to use the tunnel like that. Unfortunately, the rules regarding the person who does cast it are explicit: "Any range greater than personal..." While I think it's suggestive that you actually need to target your own tunnel with the appropriate range, I don't find that the burden of proof for the RAW has been met. As such, while I would personally require that the magus target the tunnel, that doesn't seem to be what the rules actually require.
Indeed. In this both core rules and HP p.79 agree. If you wish to introduce complications, you should explain their reason to your troupe.
ReVI tunnels replace a spell's Range parameter with the tunnel's Range parameter. When casting through a tunnel, your spell's target must include the tunnel's target (HP p.79), but not the tunnel proper.
HP p.79 allows spells of certain Ranges to be cast through a ReVi tunnel from a place distant from its local end. But this does not imply, that other spells of Range greater than Personal cannot be cast though that tunnel at all.
Why positing, that conditions of the spell's Range parameter (like making eye contact) need to interact with the tunnel, where this is not specified?
Well thanks for the replies: it is clear for me that if the Intangible Tunnel replaces some spells' parameters with its own (not all of them, though: I think I read somewhere that if you cast a spell of longer duration than the tunnel's, the spell continues after the spell ends), R:Eye spells could work with tunnels and things work without complications. It's also clear that I misunderstood the Tethered Magic virtue.
Regarding magi being able to cast each other R:Eye spells without being face to face, but through an effect that lets them see each other, makes me confused about spell parameters and what happen to these spells when other effects alter these parameters. But that's something to think about (and maybe another thread).