D&D 5E Spell interaction conundrum

[Gilladian]

Does Wall of Force stop a Mage Hand (in 5e)? If not, what WOULD stop Mage Hand from being able to be used to flip a lever that is visible, but located beyond a wall of force?

Relevant spell texts:

MH says "a spectral floating hand appears at a point you choose within range."

WoF says "Nothing can physically pass through the wall."

So is a spectral hand (which CAN interact with physical objects, and can lift up to 10 lbs of weight) really physical? Or not? And if not, what could block it?

This is important because of a trap in a module I'm converting to 5e, which is, the way it is written, totally dependent on the wall of force to keep everyone out.

 

[Cernor]

I can't remember the page, but I remember reading somewhere that if you try to target a spell on the opposite side of a barrier, it comes into effect on the side closest to you. Will edit once I find it.

Edit: In the PHB on page 204, it says "If you place an area of effect at a point 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."

Wall of Force is invisible (so doesn't satisfy the condition that you can't see where you're casting it), so I'd rule that you'd be able to create the hand on the other side of the wall... But the hand wouldn't be able to pass through the wall.

 

[fjw70]

I wouldn't allow creating an effect on the opposite side of an obstruction. The rules don't specifically disallow it but that is the way I would run it.

 

[Gilladian]

I can't remember the page, but I remember reading somewhere that if you try to target a spell on the opposite side of a barrier, it comes into effect on the side closest to you. Will edit once I find it.

Edit: In the PHB on page 204, it says "If you place an area of effect at a point 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."

Wall of Force is invisible (so doesn't satisfy the condition that you can't see where you're casting it), so I'd rule that you'd be able to create the hand on the other side of the wall... But the hand wouldn't be able to pass through the wall.

Yeah, that's what I'm afraid of. So they can pull the lever without ever having to worry. And the wizard who supposedly trapped himself on the far side due to carelessness would have simply used the spell to set himself free. Not to mention that he could easily have asked anyone he knew to show up and set him free if he'd wanted to... the whole trap/concept is deeply flawed, if anyone bothers to question it even a tiny bit...

So if you wanted to design a trap that a wizard would cast thinking it was a legitimate spell that would simply create a protective barrier, and which would then trap him inside it, what would it need to entail? I can see it needing the following
1) no communication through said barrier. No scrying, no telepathy, etc...
2) since the wizard has an other planar servant living with him, it must also cut off all other planar travel/communication.
3) proof against mage hand, because the release for the spell is a simple lever (supposed to have been "inside" the barrier, but due to the machinations of his vengeful apprentice, "accidentally" outside the barrier).

Anything else that it would need to resist?

 

[jrowland]

I think for a lot of things like this, the designers are relying on "precedent", DM fiat, etc

The precedent is Wall of Force blocks "Line of Effect" but not "Line of Sight". Most spells require line of effect to function, so mage hand would not work in that line of reasoning. DM fiat could of course rule the other way.

PHB on page 204: "If you place an area of effect at a point 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."

Personally, I'd treat the Wall of Force as an "Obstruction" and the Mage Hand would be on the casters side as a result.

 

[Nergal Pendragon]

If you need to block it, just say the interaction of the two spells causes a localized explosion that cancels the hand spell.

If all else fails, resort to explosions. After all, magic is volatile and dangerous.

 

[Gilladian]

If you need to block it, just say the interaction of the two spells causes a localized explosion that cancels the hand spell.

If all else fails, resort to explosions. After all, magic is volatile and dangerous.

You know, that does sound like a good idea

I do think I will go with the ruling that the hand just appears on the PCs side of the wall of force. I'm also going to drop a tidbit about how the apprentice who corrupted the spell's placement (to put the lever on the wrong side) also made it "communication proof". That should be enough to hold the scenario together, if they don't ask too many questions!

 

[Voort]

So if you wanted to design a trap that a wizard would cast thinking it was a legitimate spell that would simply create a protective barrier, and which would then trap him inside it, what would it need to entail? I can see it needing the following
1) no communication through said barrier. No scrying, no telepathy, etc...
2) since the wizard has an other planar servant living with him, it must also cut off all other planar travel/communication.
3) proof against mage hand, because the release for the spell is a simple lever (supposed to have been "inside" the barrier, but due to the machinations of his vengeful apprentice, "accidentally" outside the barrier).

Anything else that it would need to resist?

First thing that comes to mind is a defensive/protective usage of the Imprisonment spell, either the Burial or Minimus Containment version. What should have been an easy hide/call for help effect was ruined when the apprentice altered the conditions for ending the spell.

 

[Paraxis]

The hand appears on the other side of the wall. It is not an area of effect spell. It summons into existence a hand of force at a point you can see within range. If you want to not have it appear somewhere either block line of sight, make that point out of the range of the spell, or place the location in an anti-magic field.

So just use two walls of force 35 feet apart from each other with the wizard on one far side and the switch on the other.
Place the switch in a globe of darkness.
Place the switch in an anti-magic zone.

 

[GameOgre]

I would rule you can't create a mage hand on the other side as well. Either way make the call and move on with it and use that new reality in the future.

If I was playing I would be fine with it either way, just don't change it once it's decided.

On the other hand.....if he is stuck there and will eventually die....I wouldn't think that would be very fun. I might just figure out something else based on fun factor.