Wall of Force and Summon Spells?

[jcfiala]

Hi.

I had a situation come up the other day involving a wall of force. As you may remember, it says it blocks spells, but what does that mean exactly? I'm sure if I'm casting 'fireball' or 'magic missile', then yes it blocks the spell.

But what if the effect of the spell basically starts in a separate square. If I summon a monster, can I cause it to appear on the other side of a wall? I can see that square, and nothing's going 'from' me 'to' that square that I can think of.

Similar question with something like Spiritual Weapon.

Thanks!

 

[Plane Sailing]

I'm afraid you can't, because wall of force blocks line of effect, and line of effect is required between you and the point at which the creature is summoned.

Back in 3.0 you had a neat trick of sitting behind your wall of force and summoning creatures that could teleport to the other side to attack on your behalf (from lantern archons upwards), but sadly that loophole was closed in 3.5e since your summoned creatures can no longer teleport.


Cheers

 

[AuraSeer]

No matter what spell you're casting, you need "line of effect" to its origin point. Line of effect is blocked by a solid object, like a wall, unless there is a one-foot square opening for the effect to pass through.

Look in the Magic Overview section of the SRD or PH, and read the rules on line of effect.

 

[dcollins]

From the SRD "Magic Overview: Aiming a Spell":

Line of Effect: A line of effect is a straight, unblocked path that indicates what a spell can affect. A line of effect is canceled by a solid barrier. It’s like line of sight for ranged weapons, except that it’s not blocked by fog, darkness, and other factors that limit normal sight.

You must have a clear line of effect to any target that you cast a spell on or to any space in which you wish to create an effect. You must have a clear line of effect to the point of origin of any spell you cast.

A burst, cone, cylinder, or emanation spell affects only an area, creatures, or objects to which it has line of effect from its origin (a spherical burst’s center point, a cone-shaped burst’s starting point, a cylinder’s circle, or an emanation’s point of origin).

An otherwise solid barrier with a hole of at least 1 square foot through it does not block a spell’s line of effect. Such an opening means that the 5-foot length of wall containing the hole is no longer considered a barrier for purposes of a spell’s line of effect.

 

[Caliban]

A question along similar lines: Do you need line of effect to direct a spell effect that is already in place?

This came up in a game I was running: Mystic Theurge casts Defenestrating Sphere, then casts Otiluke's Resilient Sphere on himself. Can he still direct the Defenestrating Sphere from inside the Resilient Sphere? Same thing would apply to spells like Spiritual Weapon or Flaming Sphere.

I ruled that he couldn't control it without line of effect to the spell, but I haven't had time to really research the issue.

 

[Starglim]

A question along similar lines: Do you need line of effect to direct a spell effect that is already in place?

I don't see anything in the description of Direct a Spell that helps explicitly.

There's no requirement to speak aloud or have your hands free, so most likely directing a spell is a mental impulse (I'm sure that has been debated so feel free to correct me). The extent to which mental impulses can penetrate barriers is suggested by message and detect thoughts. Unfortunately, neither one specifies whether it is blocked by a wall of force. Fortunately, the description for wall of force suffices:

Breath weapons and spells cannot pass through the wall in either direction

There are some specific exceptions, but message and detect thoughts are not among them, so they do not pass through. Thus if these analogies are valid then control of the spell cannot pass through the wall.

However, I could perhaps make the argument that the only relevant requirement to direct a spiritual weapon is that it remains in your sight - nothing interpretable as line of effect is mentioned - therefore it is a gaze effect, therefore it passes through the barrier.

edit: To sum up, I'm still unsure. Could go either way.