D&D 5E Wall of Force and spells

[Stalker0]

There's no particular reason a solid object blocks magic just because.

The because is "because the rules say so"

The rules tell us that not being able to see a target prevents you from targeting them. They tell us that total cover can block targeting. But it's up to the DM to decide what can actually obstruct magic.

As always the DM is welcome to make any ruling they want. But the RAW is clear on this, if something provides total cover it blocks magic. Its the arrow test, if I can't fire an arrow and hit you, I can't hit you with a targeted spell. Its that simple.

 

[Stalker0]

The real things I'm unsure of are Hypnotic Pattern and Fear.

Lets take a look.

Hypnotic Pattern is a 30 foot cube. The creatures must be "within the area" to be affected. So seeing the pattern isn't enough, you must actually be present where teh area of the spell is placed. Therefore, its a question of "can I put a hypnotic patern within a wall of force"

The rules for area effect:

Targets​

...
A spell's description tells you whether the spell targets creatures, objects, or a point of origin for an area of effect (described below).

A Clear Path to the Target​

To target something, you must have a clear path to it, so it can't be behind total cover. If you place an area of effect at a point that you can't see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.


So the rules for area effects are pretty clear here. Now note....you do not have to be able to see the point you want to target with hypnotic pattern, you can throw it right into a pit of darkness no problem. However, if there is total cover, the spell "goes off early" and expands out from the near side of the wall.

So in the case of a wall of force, you can't get the area within the sphere, and so cannot effect targets within the sphere with hypnotic pattern.


Now how about Fear? Fear doesn't have targets but has a 30 ft cone area. Can the cone go through the wall of force?

The relevant passage is once again found in the section on Area of Effect.

Areas of Effect​

...
A spell's effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn't included in the spell's area. To block one of these imaginary lines, an obstruction must provide total cover.


So this passage tells us that a cone cannot bypass total cover, because once you get passed the wall.... the squares no longer have unblocked straight lines back to the point of origin (which is the caster), and so that location isn't included in teh spell's area.

 

[Stalker0]

Ok so rereading the rules on Summoning (more specifically conjuring) I think I've been led wrong before when I've been told you can't summon behind a wall of force. Take Conjure Animals as an example.

Conjure Animals​

Concentration
LEVEL
3rd
CASTING TIME
1 Action
RANGE/AREA
60 ft
COMPONENTS
V, S
DURATION
Concentration 1 Hour
SCHOOL
Conjuration
ATTACK/SAVE
None
DAMAGE/EFFECT
Summoning

You summon fey spirits that take the form of beasts and appear in unoccupied spaces that you can see within range....

So conjure animals doesn't have a target nor does it have an area of effect, which are the only two things that the book specifies as needing a clear path to the target. the spell in this case does note that the origin of the spell must be

• Unoccupied
• Somewhere you can see

But otherwise cover has no relevance. So it seems you can in fact summon through a wall of force no problem.

 

[ECMO3]

Psychic lance requires you to see the target.

Not if you say the target's name - "You unleash a shimmering lance of psychic power from your forehead at a creature that you can see within range. Alternatively, you can utter a creature’s name."

So, that is stopped. Plane Shift requires reach - so, it was already blocked.

I am talking about the caster plane shifting from another plane .... or for that matter into a building on a different plane or out of a building to a different plane (i.e. through a wall)

True, Dimension Door would still function. Not particularly concerned about that. Kinda the same with Scrying.

But the same rule that would stop psychic Lance would also stop these if rigorously applied. If magic can't penetrate cover than scrying can't penetrate cover and plane shift can't penetrate cover.

 

[Oofta]

Not if you say the target's name - "You unleash a shimmering lance of psychic power from your forehead at a creature that you can see within range. Alternatively, you can utter a creature’s name."



I am talking about the caster plane shifting from another plane .... or for that matter into a building on a different plane or out of a building to a different plane (i.e. through a wall)



But the same rule that would stop psychic Lance would also stop these if rigorously applie.

Uttering the creature's name is just a work-around for if you cannot see them but they are not otherwise behind total cover. The target/area is still 120 feet, which is all that matters.

 

[Lanefan]

We disagree. A wall of force acts as a solid object, just one that happens to be transparent to visible light. It's the way it's always worked in any game I've ever played.

Quoting the same rules passage you posted upthread:

===============================

A Clear Path to the Target​

To target something, you must have a clear path to it, so it can’t be behind total cover.
If you place an area of effect at a point that you can’t see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.
================================

The bolded clause (emphasis mine) affects the entire rest of the sentence. If you can see the target point, all the rest doesn't apply.

Take out that bolded clause and it works exactly the way you seem to think it does. Leave that clause in, and you can affect something behind a transparent obstruction unless something physical has to pass through said obstruction.

As is, it's either a) very poorly worded or b) the intent really is that you can cast some spells through glass or a WoF.

 

[Oofta]

Quoting the same rules passage you posted upthread:

===============================

A Clear Path to the Target​

To target something, you must have a clear path to it, so it can’t be behind total cover.
If you place an area of effect at a point that you can’t see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.
================================

The bolded clause (emphasis mine) affects the entire rest of the sentence. If you can see the target point, all the rest doesn't apply.

Take out that bolded clause and it works exactly the way you seem to think it does. Leave that clause in, and you can affect something behind a transparent obstruction unless something physical has to pass through said obstruction.

As is, it's either a) very poorly worded or b) the intent really is that you can cast some spells through glass or a WoF.

All I can say is how I run it, how everyone I know runs it.

 

[James Gasik]

So if you can't cast spells on people without a clear path, which is obstructed by total cover, how does something like Dream work?

Relevant text: "Choose a creature known to you as the target of this spell. The target must be on the same plane of existence as you"

 

[Lanefan]

So if you can't cast spells on people without a clear path, which is obstructed by total cover, how does something like Dream work?

Relevant text: "Choose a creature known to you as the target of this spell. The target must be on the same plane of existence as you"

More crap wording.

Why not have it say: "Choose a single creature that is both known to you and on the same plane of existence as you". There. Out comes the confusing word "target", and it's just as easy to parse otherwise.

 

[Hussar]

So if you can't cast spells on people without a clear path, which is obstructed by total cover, how does something like Dream work?

Relevant text: "Choose a creature known to you as the target of this spell. The target must be on the same plane of existence as you"

Specific trumps general.

Same as scry or even detect thought or dimension door.