Question about web

[parinho7]

These masses must be anchored to two or more solid and diametrically opposed points or else the web collapses upon itself and disappears.

Does this mean that you can't cast web on the floor? Two floor tiles can be diametrically opposed but can the web be anchored to them? Does it need to grip on them?

 

[the Jester]

Two floor tiles are adjacent, but not diametrically opposed.

You need a floor and ceiling, two walls, a wall and a pillar, two pillars, etc. Think of how spiders do it- they stretch their webs from one anchor to the next.

 

[parinho7]

I don't quite get it So if one side of it is attached to the ceiling and the other to the floor how the 20 ft. radius is going to take effect? Will it have the shape of a cube? If I cast it between two pillars is it also like a cube? Will it have a depth of 20 feet??? I don't get it!! Help please

EDIT:

Maybe the following lines are confusing me

Anyone in the effect’s area when the spell is cast must make a Reflex save. If this save succeeds, the creature is entangled, but not prevented from moving, though moving is more difficult than normal for being entangled (see below). If the save fails, the creature is entangled and can’t move from its space, but can break loose by spending 1 round and making a DC 20 Strength check or a DC 25 Escape Artist check. Once loose (either by making the initial Reflex save or a later Strength check or Escape Artist check), a creature remains entangled, but may move through the web very slowly. Each round devoted to moving allows the creature to make a new Strength check or Escape Artist check. The creature moves 5 feet for each full 5 points by which the check result exceeds 10.

Let's say I cast it between two pillars. This is going to create a surface of webs. I suppose that it's thickness is less than 5 feet. So if someone who remains entangled but moves by 5 feet won't he be 5 feet away from the web area??
Unless he stretches the web but won't that make it difficult for calculating where the web is exactly on the battle grid? And also what is the meaning of mentioning the 20ft. spread in the spell description. Does it mean the maximum area that the web can occupy?

 

[the Jester]

You center the web on an origin point and it is a 20' radius spread, so the shape depends on the area you cast it in. It starts as a sphere, but intervening walls or whatever can get in the way; as a spread, it can turn corners, kind of like fog.

If you cast web between two pillars, I believe it works just fine. The way I read it, it doesn't matter how much of the web is anchored as long as it's anchored. From the 3.5 PH:

Web creates a many-layered mass of strong, sticky strands. These strands trap those caught in them. The strands are similar to spider webs but far larger and tougher. These masses must be anchored to two or more solid and diametrically opposed points- floor and ceiling, opposite walls, or the like- or else the teh web collapses upon itself and disappears.

While I suppose some dms might only allow the web between two pillars to stretch between those two pillars, I think a strict reading of the RAW supports the position that two anchors take care of the whole web.

But, if you're a player and not the dm, I'd check with your dm on how he rules on this one.

 

[Vegepygmy]

While I suppose some dms might only allow the web between two pillars to stretch between those two pillars, I think a strict reading of the RAW supports the position that two anchors take care of the whole web.

I agree. Web is an extremely powerful spell, and the "anchor points" requirement is vital to keeping it balanced (IMO), but there's no need to be extreme about it.