Sight and magic questions

[Sander_Kaa]

Dear forum-members,

I'm DM for quite some time for a D&D 3.5 group. However, I still have problems with Line of Sight issues (Line of Effect is clear to me).

The situation last night:
A cloud giant used his fog cloud ability and the cloud rules according to Fog Cloud :: d20srd.org with basically means a radius of 20 feet is filled with fog which hampers sight beyond 5 feet.

Outside the fog was a beguiler who wanted to cast confusion (Confusion :: d20srd.org) somewhere inside the fog (hoping to catch the giant with it). I ruled that the point he wanted to designate as the origin of the burst must be visible for him (which rendered it useless at that moment because al visible spots led to including allies in hus confusion burst).

The player was not happy with this (which I understood, he wanted to get rid of the cloud giant smashing his friend) but I want to know if my ruling was correct (and why or why not).

 

[irdeggman]

Line of effect is different than line of sight.

I'm going to the Rules Compendium pg 80-81.

""A line of effect is a straight unblicked path that indicates what an ability, effect, or spell can affect. A solid barrier cancels line of effect. Fog, darkness, and other factors that limit sight don't block line of effect.

You must have line of effect to any target that you cast a spell on or to any space in which you wish to creat an effect. You must have a line of effect to the point of origin of any spell you cast, such as the center of a fireball. A burst, cone, cylinder, or emanation spell aftecs only an area , creatures, or objects to which it has line of effect from the point of origin. . ."

So baring something I've missed, you were incorrect in your ruling.

 

[Sander_Kaa]

Thanks, I exactly found the same referance. It is clear one needs line of effect to effect the area. But can the caster also designate the origin point on a place he can't see?

EDIT:

To support my decision I found the following:

Aiming A Spell

You must make some choice about whom the spell is to affect or where the effect is to originate, depending on the type of spell. The next entry in a spell description defines the spell’s target (or targets), its effect, or its area, as appropriate.
Target or Targets

Some spells have a target or targets. You cast these spells on creatures or objects, as defined by the spell itself. You must be able to see or touch the target, and you must specifically choose that target. You do not have to select your target until you finish casting the spell.

and

Burst, Emanation, or Spread

Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell’s point of origin and measure its effect from that point.
A burst spell affects whatever it catches in its area, even including creatures that you can’t see. It can’t affect creatures with total cover from its point of origin (in other words, its effects don’t extend around corners). The default shape for a burst effect is a sphere, but some burst spells are specifically described as cone-shaped. A burst’s area defines how far from the point of origin the spell’s effect extends.

First, the spell 'confusion' has a target (a point in space) which the caster needs to see. Then from the point of origin the burst takes control and catch everything within (without nescessity of line of sight). But still I'm not 100% sure.

 

[Hexer]

hmmm but a point in space is not a creature or object as described under "Burst, Emanation, or Spread", is it?Seems to me if "a point in space" was considered a target as used in that description, a whole lot of spells would be of the "target" type, basically all area-effect spells...

I'm not sure (especially being someone who's pretty new to D&D and pen&paper roleplaying generally) but I'd think one could just as well judge that no line of sight is needed

 

[Empirate]

A spell's target is that which is defined as a 'Target' under the entry of the same name in the header of the spell's description. If the spell description's header has no 'Target' entry, it is not a targeted spell, but an Effect and/or an Area spell.

Effect

Some spells create or summon things rather than affecting things that are already present.
You must designate the location where these things are to appear, either by seeing it or defining it. Range determines how far away an effect can appear, but if the effect is mobile it can move regardless of the spell’s range.

This entry does not pertain to Area spells, obviously; nonetheless, it brings up the interesting point that not all spells must have a point of origin that you can see.

Area

Some spells affect an area. Sometimes a spell description specifies a specially defined area, but usually an area falls into one of the categories defined below.
Regardless of the shape of the area, you select the point where the spell originates, but otherwise you don’t control which creatures or objects the spell affects. The point of origin of a spell is always a grid intersection. When determining whether a given creature is within the area of a spell, count out the distance from the point of origin in squares just as you do when moving a character or when determining the range for a ranged attack. The only difference is that instead of counting from the center of one square to the center of the next, you count from intersection to intersection.

Note that you 'select' an Area spell's point of origin - there is no mention of being able to see it. While I cannot prove ex negativo that you do not, in fact, have to be able to see it, to me it seems strongly implied that you can 'define' the point of origin without line of sight, as given under the 'Effect' description above.

Further note that with such spells as Dimension Door (not to speak of Teleport or Clairaudience/Clairvoyance), you are free to define your target destination by 'visualizing' it - further evidence that spells can affect things out of the caster's line of sight.

While this does not constitute proof that a caster does not have to be able to see an Area spell's point of origin, in my opinion it implies this interpretation, rather than its opposite.

 

[irdeggman]

First, the spell 'confusion' has a target (a point in space) which the caster needs to see. Then from the point of origin the burst takes control and catch everything within (without nescessity of line of sight). But still I'm not 100% sure.

Actually it does not have a target (a point in space).

As written it has a target "All creatures in a 15-ft radius burst".

No where does it specifically state the target is the point in space.

Now that is the only "logical" way to read the text, but there is a difference.

Personnally I think the use of "burst" clearly defines the intent of the spell - that it function as a "burst".

I don't think it should have listed "targets" but rather have an effect of "all creatures within a 15 ft burst" which would have greatly helped here, IMO.

Let's look at some other applications.

Fireball is a burst (actually a spread but for purposes of this arguement it functions similar enough and people have been using fireball for a very, very long time in-game) that specifies you point and name a distance. Since it is a spread you get to pick which corner of the square to center the fireball on - even if you can't see the square.

 

[Vegepygmy]

First, the spell 'confusion' has a target (a point in space) which the caster needs to see.

Confusion is indeed a targeted spell; but the target is not a point in space, the targets are the creatures within the 15-ft.-radius burst. Thus, the caster could cast confusion into the cloud, but it cannot affect any creature the caster can't see (or touch).

It's extremely odd, but that's how it works as written.

 

[Empirate]

Wow, Confusion IS targeted... nevertheless, I believe for non-targeted Area spells you don't need line of sight.

 

[irdeggman]

Confusion is indeed a targeted spell; but the target is not a point in space, the targets are the creatures within the 15-ft.-radius burst. Thus, the caster could cast confusion into the cloud, but it cannot affect any creature the caster can't see (or touch).

It's extremely odd, but that's how it works as written.

This is how it would work as written. Good summary.

I agree with the assessment of it being extremely odd (and probably poorly written).