Wall of Thorns

[Togo]

A question about the spell wall of thorns. It's a barrier, given time and damage you can move through it. Does it block line of sight, line of effect? Can you shoot through it? Does it block weapons, reach weapons, etc?

I can make up a ruling of course, but interested in what interpretation the rules best support.

[Biffoniacus_Furiou]

Other barrier-type spells whose effect grants cover and/or concealment always point that out in the description. Wall of Thorns does not grant either of those, because it does not say that it does. It only serves to hinder creatures, not attacks.

[eggynack]

Other barrier-type spells whose effect grants cover and/or concealment always point that out in the description. Wall of Thorns does not grant either of those, because it does not say that it does. It only serves to hinder creatures, not attacks.
Wall of stone doesn't.

[Biffoniacus_Furiou]

Wall of stone doesn't.

A solid wall of stone has obvious effects. A tangled mass of thorny brambles should have sufficient open space to see and attack through.

I played paintball in the woods and we found a really bad spot that was nothing but thorny branches, you couldn't move through it but it was easy enough to shoot through. Arrows and swords are going to go through sticks and thorns that a paintball wouldn't make it through.

[eggynack]

A solid wall of stone has obvious effects. A tangled mass of thorny brambles should have sufficient open space to see and attack through.

I played paintball in the woods and we found a really bad spot that was nothing but thorny branches, you couldn't move through it but it was easy enough to shoot through. Arrows and swords are going to go through sticks and thorns that a paintball wouldn't make it through.
It really depends on how thick the thorns are, I would think, though I can't claim massive experience in the field of shooting through thorns. As is, my stance is probably that wall of thorns is close enough to undergrowth, or heavy undergrowth (http://www.d20srd.org/srd/wilderness.htm#forestTerrain), that it would provide approximately that degree of concealment.

[Piggy Knowles]

It's a DM's call, really. The wall calls itself out as a barrier, and technically in the definition of cover, any wall can provide cover (and the effect section of wall of thorns is most certainly a wall). However, line of effect only needs one foot of open space, IIRC, so the type of wall is relevant. I mean, if it's a wall like the Wall of Brambles (http://img1.wikia.nocookie.net/__cb20090916234512/mtg/images/2/2a/Wall_of_Brambles_1E.jpg), it would almost certainly block LoE/LoS. If it's more like a kiawe tree (http://2redbackpacks.files.wordpress.com/2012/03/dsc00276.jpg), it might provide concealment as heavy undergrowth, but certainly wouldn't block LoE or LoS.

I know you didn't want an "ask your DM" answer, but without the spell specifying, you're kind of on your own. As a level 5 spell, I'm inclined to assume we're talking about a serious wall, personally, so when I DM I do rule that it blocks LoE and LoS.

[Vogonjeltz]

Spell description says it's a wall of brush, and later compares it to overgrown areas. I'm inclined to think that it must be dense enough to prevent LoS and LoE if it requires 10 minutes of hacking at it to clear a 1 foot deep safe passage.