I'd allow it. Then again, I've allowed Vernean Martians, so, that's not much of a barrier.
Don't punish yourself for making cool stuff: cut the magnitude for funky. Also, I don't think it's an extra magnitude for unidirectionality in this case.
I'd note that you don't need, effectively, for it to be a wall. You could just treat this as a mass of Individual wards on your Group of people. If you really like the "stops like on a wall" effect, just work that up as how your sigil interacts with the spell. It's essentially a cosmetic effect and so it can be a freebie if its based on your sigil. Pick a cool sigil that lets you do stuff like that: it makes the game more fun.
So, if you shave off the extra three magnitudes, that gets you down under the Ritual level. A 40th level spell which deflects (all) wooden stuff for three minutes seems OK to me. You may need to explain how the members of your group can still use their wooden stuff, but I'd fiddle that on the basis that small weapons they were wearing at the time the spell is cast are "clothes". and "clothes" are allowed in Individual Targets. Alternatively, if your group is stricter about this, then kit your guys out with weapons made of metal, bone, and leather.
I don't loathe it. I just think that you need to get your troupe to explicitly permit it.
Many magic systems (in other games/worlds) do "stuff" - largely up to the undefined imagination, more or less. Not AM.
In AM, the Techniques are "verbs" and the 10 Forms are the objects of those verbs.* Rego Hebem is the mage saying "I Control Wood" in magical tems, etc. So if you can't, somehow (and within the Te/Fo definitions & guidelines), fit the effect you want into 1 of those 10 Forms, and/or 1 of the 5 Techniques... no luck.
(* In Latin, the -o ending (that all the Techniques share) is the conjugation of "I do ____" - Creo = "I create", Perdo = "I destroy", etc. In the classic "Cogito ergo sum", cogito = "I think". Note - LOTS of "irregular" verbs in Latin, so they don't all work this way.)
So to create a wall "of Force", something has to actually be there to apply that force - wind, invisible stone, something. Or a Rego Ward - that can work too, but in canon a "Warding Wall" does not exist, only Warding Circles. Not (theoretically?) impossible to make a Wall, but that would require a breakthrough of some sort.
For clarification on Wards, esp how to change a Target:Circle Ward into something a Target:Individual or T:Group, see page 114 "Magical Wards".
Convince me. Being inside an illusion does not necessarily allow you to see out (i.e. allow species in without allowing species out). Being inside the gut of an illusionary dragon lets you see what, exactly?
PeIm magic might destroy the species you emanate but does not prevent you from perceiving species.
ReIm magic, well, it would be impossible to live in a castle under the Illusion of the Misplaced Castle, because you can't see what you're doing a mile away. Terrible spell.
I don't take it insultingly. I came here looking for honest, constructive criticism. This thread has been invaluable to me. Also sometimes a noob like me can spark a discussion with merit for everyone, because us noobs ask questions that never cross an expert's mind.
The Troupe has to decide how they want to tell the story. If they look to the primary SG for guidance in that, then it falls to you alone. But you can (and should?) consult with them re what they want/don't want for the "feel" of the Saga.
Touche.
And right in both attitude and observation - I'm sure everyone here had "first spells" (or so) that were... well, cringe-worthy.
Lots of spells from other systems, even entire categories of spells, that just don't translate into Hermetic magic. (Sometimes they are in the AM world, as something from outside the Hermetic Theory).
In the early versions of AM, the Tech's and Forms were far less clearly defined, and LOTS of "outside" spells were shoe-horned into one form or another with a handwave. Some few of those still exist in the AM 5 canon - often with a comment about "unique spell" in the description.
Isn't there a one way effect in one of the source books? The one to make a wall invisible in one direction only, I remember it mentioning it being created by a Tremere to target their opponents while inside a wall. Though I don't think that was a ward, the one-way concept is alive and well.
It depends how the dragon is constructed, but yes, I mean "Imaginem spells" when I wrote illusions. 8)
There is, for example, a spell which allows species to travel one way but not the other, so that a group of people on a road can see their foes, but their foes cannot see them. It's in the Jerbiton chapter of HoH:S. There's a lot of stuff there about manipulating the movement of species which could be argued acts by filtering species.
A magus protected by Parma can cast a spell on himself (R:Per, inside the Parma) without needing any penetration.
He can cast a spell on a grog (outside of the Parma) without needing any penetration.
But the grog can't use his Enchanting Music on the magus, without substantial penetration, because it's blocked by the Parma.
So Parma is one-directional. It allows magic to go out, but not to get in.
What I meant was is it necessary for magic to cross the Parma barrier for the magus to cast spells? This delves directly into how magic works (the mechanics behind the screen that are really undefined).
In the end, all wards are filters, given they just block ONE form at a time. It's the possible application of filtering within the form that hasn't been well defined yet.
Okay, I looked at Ambush on the Deserted Road. It's a terrible spell (at being inconspicuous) if you consider the implications.
The effect is destroying all sight species traveling in one direction originating in the circle bounded area. Now think about how this works.
Let's say A, B and C are in a straight line. A and B are inside the circle, while C is outside. Species are being destroyed in the direction from A to C.
A can see B and C, the species traveling that way are not destroyed. B can see C for the same reason.
C cannot see A nor B, because the species traveling that way are being destroyed.
However, B cannot see A, because the species traveling that way are being destroyed. In fact, B cannot see anything inside the circle in the line from A to C, including the ground. Whether or not this makes it appear as an infinitely deep hole probably isn't relevant, but it might be scary. Also, C can't see anything in the circle at all. The grass, the ground, nothing. There's a big (black?) HOLE where the circle is, as far as C is concerned. This is hardly what I'd call inconspicuous. Large circular holes tend to get noticed. Note that stuff outside the circle might camouflage the effect, depending on the viewing angle. I think a Ring/Group Invisibility spell would be a LOT more effective for lurking in ambush.
Now, is it a one way ward? No, because it doesn't BLOCK/STOP anything at all. Species travel freely through the entire area, and only species originating from within the circle traveling in a specific direction are destroyed. Filter? Yes. Ward? No.
An Imaginem ward would be interesting. A personal ReIm ward would effectively blind the user (or deafen, etc) as species were blocked from reaching him. He would appear as a blank spot in front of things (human shaped blank mass?), as he could not emit species through the ward, even though he would be illuminated, and species cannot pass through him so he would not be invisible.
Oddly enough, PeIm magic should do roughly the same thing (blank mass), given that just because a person isn't emitting species doesn't mean that the exterior species can freely pass through them. We'll give invisibility a free pass on this one, I guess, though functionally it should require a Rego requisite to move those outside species directly through/around the magus. This may be an Anamorphic function (viewers ignore the impossible blank spot and fill in the details themselves, creating a seamless illusion of invisibility). Though if you made a wall invisible your mind really couldn't fill in the details; so invisible things don't block species, at least if we want PeIm magic to actually be useful. This means, however, that you could make a wall invisible to sound and hear what was on the other side clearly, as destroying the ability of something to emit species renders it transparent to those species (or seems to).
Another question: Does Ward Against Heat and Flames prevent you from appearing warm to Vision of Heat's Light? If not, then it's a one-way ward.
Touche.