Can you cast a spell behind Wall of Force?

Wall of force: "Nothing can physically pass through the wall. It is immune to all damage and can’t be dispelled by Dispel Magic."

Synaptic static: "You cause psychic energy to erupt at a point within range."

Id allow it.  

Im not sure what id do if he tried something like eldritch blast, which says :"You hurl a beam of crackling energy."

I think a beam might be physical?

Google results keep saying wall of force provides "total cover" but thats not in the 2024 spell description.

I think a spell that describes a "beam" or "bolt of lightning" or a "ball of fire" going from the caster to the target would not go through, but a spell that just materializes at the target would work despite the wof.

I remember building a character years ago around subtle casting as much as possible, and that was when i learned that a LOT of spells have beams of energy coming from the caster to the target.  So i could subtle cast the spell, but everyone would know it came from me anyway.

It takes a very judicious spell selection to do subtle casting and have no other visible effects that indicate you were the caster.

"A Clear Path to the Target. To target something with a spell, a caster must have a clear path to it,"

Yeah, I'd still rule that any spell description lacking a "beam" of energy or "bolt" of fire or whatever going from caster to target ignores cover.

There is "cover" and there is "concealment". "cover" is defined as anything that actually stops a bullet, shrapnel, a bomb blast, etc. A foxhole or trench provides cover from small arms fire and at least some indirect fire such as artillerty. A wall of sandbags provides cover.  Getting behind a concrete wall or armored vehicle will provide cover.

"concealment" is defined as something that hides you from enemy observation. A camo colored tarp can provide concealment. If you are under a camo colored tarp in the woods, you may be concealed. But if the enemy tries to recon your position by fire, that tarp is useless cover. The smallest bullet will go through you.

DND doesn't really handle this in teh rules. At all.

Concealment, in DND, is broken down into VISIBLE or INVISIBLE. That's pretty much it. If you successfully conceal yourself via a stealth check, you gain the invisible condition. if not, you are completely visible. There's also FULLY OBSCURED and LIGHTLY OBSCURED, which are a different way of looking at concealment. And this results in such as two humans both hiding in total darkness, shooting atrows at each other, all the advantages and disadvantages cancel out, and the archer attack roll is a normal 1d20 to hit.

Cover, in DND is broken down into HALF cover (+2 to your ac), THREE-QUARTER cover (+5 to your ac) and FULL cover (cannot be targeted).  Cover here, means it stops an arrow. It stops the thing being thrown at the target. If the goblin is hiding behind a tarp, they do NOT have cover. The archer can still shoot through the tarp.  the goblin is behind full cover, the archer rolls their tohit at disadvantage, but if they hit, it goes through the tarp and hits the goblin.

which results in one of the most illogical outcomes in DND: If an enemy is behind full concealment that can be shot through, like a tarp, cast magical Darkness on them first, and you can use a normal attack roll for your tohit roll. whereas if they are simply behind full concealment that can be shot through, like a tarp, the attack roll is at disadvantage.

Oh, DND, sometimes your rules just kill me.

Now, what about COVER and AOE spells?  Fireball says: "A bright streak flashes from you to a point you choose within range and then blossoms with a low roar into a fiery explosion. Each creature in a 20-foot-radius Sphere centered on that point makes a Dexterity saving throw," 

Rules: "A target with half cover has a +2 bonus to AC and Dexterity saving throws."
"A target with three-quarters cover has a +5 bonus to AC and Dexterity saving throws. "

Great. So a goblin is in a foxhole, and a fireball targets the ground in front of them. They should get +2 or +5 to their DEX save from the foxhole. Cool.

But what about FULL COVER?

RULES: "A target with total cover can't be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle."

You see the mistake they made right there???  "A target has total cover if it is completely concealed by an obstacle."

That's not how it works. COVER is something that can stop the damage. CONCEALMENT is a camo colored tarp. COVER is sandbags and foxholes. CONCEALMENT is putting mud on your face to be harder to spot with a perception check. That rule right there is completely bonkers: "A target has COVER is if it CONCEALED". NOPE. absolutely not. A target does NOT HAVE COVER by simply being UNDER A TARP. It must be fully behind something thst csn stop the damage to have full cover.

The rules do an absolutely HORRIBLE job of trying to deal with concealment. If target is invisoble, you attack with disadvantage. So cast Fog Cloud on you then shoot at invisible creature, and the attack roll is normal?? Firing at a goblin behind a tarp is at disadvantage? Firing at a goblin behind a tarp AND you are in a Fog Cloud is back to a noraml attack roll??? REALLY?  You're killing me, Smalls.

The rules do a "meh" job of COVER. half cover is +2.  three-quarter cover is +5. You can apply these to Dex saves when the target is behind a partial wall or in a fox hole. 

But then the rules just completely BOTCH it at full cover, and mix COVER and CONCEALMENT as if they are the same thing, when they are not. I'm sorry, but a goblin behind a ten foot tarp is not getting any DEX save bonus. The tarp provides CONCEALMENT, but NO COVER, and therefore NO dex save bonus. 

got an army of goblins before you in trenches and fox holes and bunkers? Use any spell OTHER than a DEX save, and those bunkers and trenches provide ZERO benefit.

"A target has total cover if it is completely covered  by an obstacle capable of stopping the attacking damage" 

Fixed it for you.

If a goblin is behind a tarp, they have zero cover from an archer's arrow. The arrow can go right through it. Now, TARGETTING the goblin behind that tarp will be harder, it will be at disadvantage, and that makes sense. BUt if you want, cast fog cloud first, and then roll your attack as normal.  (TWITCH)

Now, back to this "a pane of glass is total cover for a meteor swarm spell" silliness.

I don't care what the rules say, because the rules clearly don't know cover from concealment, and the rules say a tarp will completely protect a goblin from a fireball, . And the rules also say shooting an arrow at a goblin behind a tarp is easier if the archer is also in a fog cloud. So, no. The rules are busted. I don't know how to fix the fog cloud silliness. but that's not the question here. The question here is this little gem:

"A Clear Path to the Target. To target something with a spell, a caster must have a clear path to it, so it can’t be behind Total Cover."

Is a pane of glass "cover"??? 

If a spell says "A bright streak flashes from you to a point you choose within range and then blossoms with a low roar" then the question is does the glass stop that streak? Air didn't. But glass does? A tarp does? how about a mesh window screen? A ten foot square of translucent lace? Webbing? Does the beam need a 1 inch opening to pass through the distance from the caster to target?

I dunno. Apparently spell beams have all the force of the wisp of wind made by a butterfly's wing. a tissue paper will stop it. Does it blow up where the paper is located? Or does it wizzle into nothing? I dunno. 

But spells that dont' mention a beam of energy going from caster to target? 

Synaptic Static: "You cause psychic energy to erupt at a point within range" 

There is nothign in that spell description that says anything physical travels from the caster to teh target here.  Nothing has to pass through that sheet of glass to get to the target. No beam is described in the spell description. And if the rules dont say it happens, it doesnt happen.

Wall of Force says "Nothing can physically pass through the wall. It is immune to all damage and can’t be dispelled by Dispel Magic. A Disintegrate spell destroys the wall instantly, however. The wall also extends into the Ethereal Plane and blocks ethereal travel through the wall."

That's a weird choice of words. Why say nothing PHYSCIAL can pass through the wall unless they INTEND to allow magical effects to pass through? 

It's possible the rules for Wall fo Force assume that the "A Clear Path to the Target." caveat prevents all  spells. But that rule says ""A Clear Path to the Target. To target something with a spell, a caster must have a clear path to it, so it can’t be behind Total Cover."  OK. What is COVER? Anything that stops the incoming damage. Does wall of force stop magical damage? It doesn't say so. It says it stops all PHYSICAL things. So does wall of force provide COVER to magical effects? 

Not explicitly.

Maybe spells that describe a beam going from caster to target, that beam is physical? so it can't pass through WOF? ANd if you target a fireball to explode just outside a wall of force, the fire damage is potentially PHYSICAL damage, fire being physical and all.

If the spell has a DEX save, total cover  rules negate the spell. If the spell describes physical effects, like a beam going from caster to target, maybe beams are physical and are stopped by wall of force.

But Synaptic Static? Eh? I'm not so sure. It doesn't describe any kind of beam going from caster to target so you might be able to center the Synaptic Static AOE at the very center of a wall of force set up in a spherical shape. Nothing in the rules for synaptic static describe anything passing through the space from caster to target. And if the rules dont say it, it doesn't happen. So, it SHOULD be able to target the center of the wall of force sphere. 

and even if Synaptic Static can NOT penetrate wall of force to target the center, the AOE creates PSYCHIC DAMAGE that uses an INTELLIGENCE SAVE.

HALF COVER and THREE-QUARTERS COVER is defined in the RULES as providing +2 and +5 to DEXTERITY SAVES ONLY.

therefore COVER DOESN"T EVEN APPLY TO INT SAVES for effects that are not physical.

so even if synaptic static cannot TARGET the center of a wall of force sphere (and I think it CAN, but lets just pretend for a moment), the resulting AOE is a INT SAVE of PSYCHIC damage. INT saves are unaffected by COVER. and PSYCHIC damage is NOT PHYSICAL, so you could target the center of Synaptic Static AOE to be at the edge of the spherical wall of force, and the INT save PSYCHIC damage aoe should pass through the wall of force to the range of the AOD radius.

Detect Thoughts can go through anything, up to just short of 1 foot of stone, dirt, or wood; 1 inch of metal; or a thin sheet of lead. You should be able to target someone behind a pane of glass with Detect Thoughts because the spell explicitely lists what provides COVER for detect thoughts: 1 foot of stone/dirt/wood, 1 inch metal, sheet of lead.  Glass isn't cover. COVER protects against the incoming damage. And COVER only helps with DEX saves and Detect Thoughts is a WIS save.  The spell gives an explicit list of things that provide cover, protection from the effect od thr spell. storne, dirt, wood, metal, lead, if youre behind that, you have total cover, if not, you have zero cover. 

so the caster could cast Detecr Thoughts and target someone inside a spherical wall of force. There is no physical beam from caster to target in the spell description, and the spell description gives a list of what provides total cover and it doesnt include force, Wall of Force says it stops only PHYSICAL effects, providing total cover to physical effects, meaning auto succeed on any DEX save. But detect thoughts is a WIS save and nothing physical is described in the spell.

So, it seems Wall fo Force stops physical things from passing through, and any spell that describes a magical beam of energy traveling from caster to target would get COVER from the wall of force preventing the spell from targeting inside the WOF sphere. But anything that does NOT use a DEX save and does NOT use soem sort of physical manifestation of damage, like poison gas or whatever, SHOULD be able to penetrate the wallof force sphere by targeting the outside of the sphere.

And any spell that does NOT describe a beam or blast or whatever going from caster to target should be able to target inside a wallo of force sphere because nothign physical is passing through the sphere, and especially if the spell does non-physical damage, such as psychic damage or imposes the charmed condition, should be able to directly target inside the wall of force sphere as if it were not there.

anyone quoting the "A Clear Path to the Target. To target something with a spell, a caster must have a clear path to it, so it can’t be behind Total Cover." rule as justification for why you can NOT target a spell inside teh wall of force will have to admit that the rule they are quoting is, on its bare face, a complete contradiction. Cover is not Concealment. While Half Cover and Three-Quarter cover give bonuses to DEX saves suggesting protection from damage like a foxhole, Full Cover definition confuses cover and concealment as the same thing and suddenly a big enough tarp is completely and total protection? Nope. Sorry. That's nonsensical.

Not gonna happen in my campaign.

Quote from ClassicCharismaCaster >>

Line of sight: If you can throw a pebble straight at a place without being blocked by anything, you can cast a spell there.

Can see: What you can literally see, is countered by Blindness, invisibility & heavy obscurement.

Eh? Which rule says "line of sight"? And which rule says "can see"?

I dont see either of those phrases in the 2024 rules for spellcasting

https://www.dndbeyond.com/sources/dnd/phb-2024/spells#Effects

 Those phrases are also not in the 2024 spell description of synaptic static.

https://www.dndbeyond.com/spells/2619129-synaptic-static