Our troupe has a dispute over how to interpret ranges and targets for Auram spells. Let's take a very concrete example to illustrate the problem.
MuAu20 TALONS OF THE WINDS [ArM5]
R: Voice, D: Diam, T: Ind
This changes «a» wind to do damage to many people.
Interpretation 1.
This can only affect people within the voice range, so the wind changed is the wind in an area described by voice range. A MuAu15 version with touch range, would do nothing useful. The wind would only affect the caster who is protected anyway.
Interpretation 2.
The spell affects an individual wind (T: Ind), which may cover an area up to 100x100 paces. ArM5, page 125: «A base Individual for Auram is a weather phenomenon that affects the area within a standard Boundary — an area one hundred paces across.» A MuAu15 version at touch range would almost always have exactly the same effect, as the wind is usually the same. The exception would be if the caster can get in lee of the wind.
Have you ever run into the question in game?
Which interpretation would you prefer?
I would go with #2, the one defined in the book. Note that with voice range you can be out of the wind (indoors, behind shelter, etc. And still affect it.
I'd also go with #2 - generally a Auram spell will be affecting an Auram target. (Wards are a sort-of exception to this).
The advantage of creating it at Voice range is that you have more certainty the wind is going to actually hit the targets you're aiming at - if you're casting it at touch range, you pretty much need a wind that's blowing straight from you to them. (I suppose you could argue that you had a single big wind that was going to automatically be covering the entire area, but I'd be leary of that interpretation applying reliably - just because an individual auram phenomenon can be an area up to 100 paces across, doesn't mean it always will be).
This actually sounds like a third interpretation, and it has some interesting implications that I had not thought about.
What I was thinking as I wrote down #2 is that the wind is a phenomenon which covers a wide area. If cast the spell on this wind (touching or otherwise), you will change the wind in the entire area, and affect friends and foes alike, leeward as well as windward. You will certainly hit a whole group as one.
You seem to imply that you affect a wind, windward from the target point. Aiming at foes in leeward, you will hit your friends next to you as well. Aiming at foes in windward, your friends are safe. It also raises the question as to how wide a wind is. If you think that the wind must blow directly from you to the enemy to use the spell at touch range, does that mean that it only can affect multiple people if they stand nicely in a row? Or how many people wide is a wind?
As to your parenthesis. What weather phenomena would you say are 100x100 paces, if not wind? I agree with what you say, a bolt of lightning is much smaller than that, so smaller phenomena clearly exists. What I would consider as very similar phenomena, like rain storms, winds, snow storms, etc. are very hard to define the boundaries for.
Hmm. Thinking about it, you should probably affect the wind that's part of the same breeze in both directions at once, rather than only downwind from you. The latter feels like it would need a "Part" target.
Clouds and rain, sometimes. (Or sometimes they'll need size magnitudes). Mist lying in the right sized hollows. Some winds may be roughly that big, but I wouldn't expect them all to be - you'd probably get "bigger" winds on days when there was a steady prevailing wind than if it was gusty.
Basically, you can use Touch, and it might be a good way to go if you're sponting in the right conditions, but a Voice range spell is going to be more reliable (although even that does still require there to be some wind to begin with).
OK. Then I see what you mean. Incidentally, this is also illustrates the argument in favour of #1 ... This other interpretation opens up for bickering over what really constitutes a wind and who's inside the wind's path and who's outside. Not necessarily a problem, if the troupe is happy to accept SG's decision on the spot, and after all the SG needs to decide if there is the slightest breeze in the first place.
I think so. Let's look look at how #1 would apply in a couple of cases:
R: Personal shouldn't be able to do anything to anyone else. But Last Flight of the Phoenix can damage people up to 10 paces away. And Dragon's Blood can injure people in melee combat with the caster, even if they aren't touching the caster, so they may be a pace or two away.
Let's go with R: Touch. Let's say I do a R: Touch CrHe spell to make a bridge. I touch the shore on one side of the river. Do you play that the bridge cannot reach the far shore because you haven't touched the far shore? But Bridge of Wood extends 20', which is much further than any typical magus can touch.
Now let's look at some Auram spells.
Air's Ghostly Form is R: Touch, but it can affect the vision of those several paces from the caster.
Circling Winds of Protection is R: Touch, but can knock people over if they're close enough to hit you with a melee weapon, even if they're not close enough for you to touch.
Fog of Confusion is R: Touch, but can affect people's vision and the like in a region up to 6 miles across.
The kicker, as it so nearly fits what you described as not working in #1:Breath of the Open Sky, which is R: Touch. How does this devastate the "visible countryside and beyond" if it can only affect things right at the caster?
There are many more examples like these. How do those who argue #1 is correct explain how these spells work? Those arguing #1 are going to see their arguments quickly fall apart in light of the great many of counterexamples in canon, even in the core book.
I'm definitely feeling that #2 is the book interpretation, but I also wouldn't call it 'obvious'. The instinct of magic is that the range is what you're hitting with your ire, the 'target' is that enemy over there. With a lot of spells, Auram in particular, people don't realize that the target is actually what you're hitting them with. Those of us who have fun manhandling the rules into awesome shapes can get that, but Creo spells to do damage aren't targetting the person. Pilum of Fire isn't 'targeting' Bobbert, it's 'targetting' a spear of flame and hitting Bobbert with it.
Regarding only damaging people 'downwind' of a touch-range spell, that requires target 'part', because you're only targetting the downwind, not the upwind.
The target is the weather phenomenon. If you summon lighting to strike, the target is the lightning. This is also why there is a +magnitude based upon unnatural for CrAu. The range Sight is used a lot because the range to clouds will be Sight. Without using Sight things are unnatural. Indoors, for example, is unnatural for Creo.
Raccoon is correct, you also need part to affect only part of the Wind.