Well, how thick is the wall then? It does apply a perception modifier, so obviously its not only two dimensional either.

It describes the wall as a forcefield. That means it must be thin. Does it matter how thin? No. Does it need to be a certain thickness to impose a perception modifier? Nope. Tinfoil is very thin, but you can't see through it. Glass is a lot thicker, but you can. The point is, you can control length and height, but not thickness.

I'm not arguing that "wall" automatically means it couldn't *possibly* be a floor. It's just, that's the best interpretation. If you don't make that interpretation, you have to deal with the abusive aspects. I think it's pretty clear that the barrier is supposed to block things, not be a cure-all platform that can bridge gaps, ignore landmines and pressure plates, etc. If you disagree, you can always rule otherwise.

My point, was i'd allow a mage to make it more like a balance beam, if he wanted to withhold the dice to make it a height of 0-1. I'd call for a gymnastics test to balance on the resulting no/low height barrier. It wouldn't be a replacement for levitate, but a work around should the mage have not learned levitate.

I'm pretty sure it wouldn't be thick enough to walk on top like a balance beam. It would be less thick than a tightrope. To me, a forcefield is not something you could ever balance on.

sure you could, it'd be just like balancing on oh say a monofilament line.

Yeah, I have to agree. There is nowhere in the book that says that the wall has depth, or is 3-dimensional. I is infinitely thin and only resists force from two directions, not 6. I can totally see a different spell that makes a physical box extending from the ground that you can do what you want with, and another that you can anchor in space (remember the drain code! )

Ok, so, say a mage is in a getaway car racing down the street, with lonestar in hot pursuit. Hes going to cast a physical barrier, to stop the car chasing them. He has a couple options, as a dome, blocking the street, which the car would probably hit and get stuck, as a dome around the car (assuming its big enough) that it'll have to break out of to continue the chase, as a wall, blocking the road, that they would have to crash through to continue the chase, or as a wall, lengthwise down the road, such that the middle of the car hits the infinitely small non-existent side (and not be able to see it either since its infinitely small) and have their car split down the middle.

Why wouldn't the barrier have a depth?

It doesn't have depth because it is not described as having depth. Remember also that this wall has no mass or friction and exists completely outside the laws of physics. You cannot extrapolate from what the spells says it does to what it would physically be able to do since there are no physics involved. It does only what it says it can do. Nothing more and nothing less.

EDIT - To address your question as to whether you can use it to cut a car in half:

If the car's direction of travel is perpendicular to wall, then it will have to break through the wall to continue. If it is traveling on a tangent parallel to the length of the barrier, the barrier will have absolutely no effect. It will not slice it in half, because there is no conflict of space (the wall has no mass and occupies no space!)

Huh, I didnt know my use of a spell would bring such a discussion. just in case you didnt know, my GM ruled it as being like a peice of paper, it has a width, but not enough to actually do anything. looks like i need to learn the levitate spell next. heh.

Nowhere is it said that the wall/barrier is frictionless. What if the wall is put at an angle such as / ? The car's middle connects at the middle of the slash, does the car that hits the wall slide alongside it, seperating from the rest of it? (Since at least part of the car would be going through part of your massless non-existant edge of the wall) while the rest would have to impact alongside the wall on the one side, pulling the rest of the car into the wall from the other side. Sadly, physics do affect cars, and if the wall is only two dimensional, then a wedge type shape like that should cleave the car into some very nice pieces (unless of course the car is able to break entirely through the wall).

Also, no ones addressed my force 2 earth wall spell, dimensions of 2x2x1 centered such that it encompasses someones head. Do they suffocate? Sure, they take 2P as per the spell description. But can they now now longer breathe? I'm sure it goes without saying that it'd effectively neutralize any enemy mage casting or counterspelling, since they can't see. And, they get no defence to it at all whatsoever. Even worse, since its sustained, they can move it to wherever they need it, without casting it again, as long as they either have a sustaining focus, or are willing to eat the -2 penalty.

not sure on earth wall, might be in a book i dont have, but I was trying to do the same thing with physical barrier, but I belive in the spell description that gases and such can pass through it, such as air. may want to double check the spell.

[Element] Wall is in street magic, p173. The reason I'm using it as an example is because it specifically states, "This wall has a height and length up to
the spell’s Force in meters, or it can be crafted as a dome with a radius and height equal to half the Force in meters. The width of the wall can be up to one meter." Thusly, clearing the rules arguement of if it has a width (unlike physical barrier). It also says, "Solid walls (earth, ice, etc.) have an Armor and Structure rating equal to the caster’s Spellcasting hits." Since earth is given as an example of a solid wall (versus something like fire or smoke) why wouldn't it make it impossible for the person to breathe if it encompassed his head? What about Ice Wall?

Lastly, another very mean combo I've just thought of. Cast your very big n nasty metal wall at home. Just have it be over nearby your other walls, out of the way. Keep it sustained on a sustaining focus. Learn shape metal also. When you need someone to die, just move the metal wall over and around their head. (As long as its 2 meters tall or more, and the 1 meter wide, this shouldn't be an issue). Then, use your shape metal spell to move the parts that aren't doing anything useful, onto other peoples heads.

I get the feeling our disagreement is due to our separate ways of viewing magic, and we won't really come to a consensus.

As to your slanted barrier, I know it would be stupid to calculate the barrier rating from the angle of intersection to the force vector, and I don't think that is how you should do it. I am merely saying that you can't think of it as a truly "physical barrier", it is more of a magical barrier on the physical plane.

As for your Earth wall surrounding magician's head:

• The magician can still perceive and project into astral.
• Yes, if he didn't dispell your barrier, he would suffocate
• Even though it does not say it in the description, you cannot breathe earth.

Sure, he can perceive, but spells themselves have auras on the astral, so wouldn't he only be able to see the spells aura on the astral? (Just like you can't see through the ground while perceiving)?