[Kelly Pedersen]

I agree that the default height for a Wall should be 4 yards. Personally, I think the +60% version of Wall should be enough to potentially trap someone with just one use, provided it's long enough - it says you can "form it into any shape you choose" at that level, and I think that's enough to allow you to reshape it into a circle, effectively. I would definitely require a big enough Wall to encircle the target without touching them, though. I think, for a standard human, that's going to require a 2-yard radius, large enough to make a 6-yard long wall. A single 1-yard radius Wall isn't quite enough to encircle a standard 1-yard hex.

Also, some can try to dodge out of this sort of thing as you cast it, with a Dodge and Drop - against a six-yard-long Wall, which effectively circles one hex, I'd give anyone a chance to dodge out, and even a wider circle could still potentially be dodgeable if someone had more than a 1-yard Step, thus allowing a longer Dodge and Drop.