Invalid Spell Targets

[tieren]

This is related to the other thread on disrupting spell casting, but I want to focus on one point of that discussion which seems to be heading off in multiple directions at once.

The point of interest to me is whether a caster can be tricked into using counterspell when no spell is actually being cast.

Now I know the casting time is "1 reaction, which you take when you see a creature within 60 feet of you casting a spell". The text goes on to assume a spell is actually being cast and what happens based on the level of the spells, etc... However, nothing in the spell says "you can tell when creatures within 60 feet of you are casting a spell".

I am taking for a baseline that there is agreement that you can not use counterspell on a spell cast using the Subtle metamagic because there is no outward sign of the casting to react to. I take this to mean there is no intrinsic "magic sense" which lets a character detect the presence of casting absent noticeable spell components (exception being actual detect magic effect).

SO let's presume a bard, with expertise in arcana and performance, the charlatan background and the actor feat [just for emphasis they are really good at acting] were to study the motions and words of a wizard casting a spell that the bard themselves does not know. Then in a combat situation the bard chooses to spend his action exactly mimicing the verbal and somatic components of said spell he does not know.

Now presume your character is an enemy of that bard and knows counterspell and have it prepared. You see the bard doing the somatic component and hear them chanting the arcane words of a spell. You tell the DM you want to use counterspell, the DM asks for a contested check between the bard's performance and your perception and the bard wins. What happens next?

1. Do you try to cast and fail?
2. Is the slot consumed?
3. Is your reaction at least consumed (such that you couldn't then use it the same round for shield spell for example)?
4. Or do you just still, despite all outward appearance and your characters own perceptions and belief, just know it isn't really a spell and don't even try to counter it?

I can imagine several similar circumstances with other spells, trying to eldritch blast an object you think is a creature (liek a statute in a dark room); or trying to cast hold person at an illusion, etc...

How are we supposed to deal with this RAW, and how do you actually address it at your table (if ever)?

[DeTess]

generally, I'd rule that such a spell would fail, and consume the spell slot, though I'd also make it quite clear why it failed in the description, so it's not a complete loss. In your specific example of the bard, I might allow that, but it'd definitely cost an action to cast a fake spell to bait out a counter spell, and some kind of bluff check against passive arcana or something similar would be involved.

[Unoriginal]

Before this conversation goes further: have you read the rules about invalid spell targets in the Xanathar's?

Here they are, just in case you or other forum goers interested in it haven't.


INVALID SPELL TARGETS
A spell specifies what a caster can target with it: any type of creature, a creature ofa certain type (humanoid or beast, for instance), an object, an area, the caster, or something else. But what happens if a spell targets something that isn’t a valid target? For example, someone might cast charm person on a creature believed to be a humanoid, not knowing that the target is in fact a vampire. If this issue comes up, handle it using the following rule.

If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target.

To do a basic summary: an invalid target does not mean that the spell is impossible to cast, just that it'll have no effect if cast, and that the absence of effect gives no direct clue as to why it failed.

I don't see much difference between trying to cast Charm Person on a vampire the caster was deceived into thinking they're an humanoid and trying to Counterspell a "Double, double toil and trouble; Fire burn and caldron bubble" fake routine the caster was deceived into thinking is an actual spell.

[tieren]

To do a basic summary: an invalid target does not mean that the spell is impossible to cast, just that it'll have no effect if cast, and that the absence of effect gives no direct clue as to why it failed.

Thank you for the citation, that does help a lot. That was what I was thinking and using myself already.

In the specific case of Counterspell a target doesn't seem to be defined. The trigger for the reaction is "when you see a creature...casting a spell".

So in this particular example, if your character sees what it believes to be a creature casting a spell (assuming all appropriate checks to verify have actually been made and failed) can the character try and fail to use counterspell per the quoted invalid target rule, OR does the trigger never occur and the character doesn't have the opportunity to cast it.

[Keravath]

I'd rule it wouldn't work RAW just based on the wording of counterspell.

"Casting Time: I reaction, which you take when you see a creature within 60 feet of you casting a spell

You attempt to interrupt a creature in the process of casting a spell."

1) You have to see them - so counterspell isn't an option if blinded or unable to see.
2) They have to be within 60'
3) They have to be casting a spell (not pretending to cast a spell).

There is nothing in the description about "pretending" to cast a spell. There is no indication of the mechanics used to know that a spell is being cast or what that spell might be. However, the wording does require that there is actually a spell being cast ... however, this information is conveyed to the magic user with counterspell.

If you want to fluff it then simply say that casting a spell causes a disturbance in the weave that is visible to a magic user within 60' who is capable of casting counterspell. If subtle metamagic is being used then this effect is suppressed.

Someone pretending to cast a spell, no matter how good at it, would then simply not be harnessing any magic and this would be visible to the caster with counterspell.


P.S. In general, the case for invalid targets applies if you cast a spell at a target that is invalid then it does nothing. However, counterspell is a reaction spell that is triggered in response to a very specific condition ... that condition is "a creature within 60 feet of you casting a spell" ... if that trigger is not met then casting counterspell isn't possible. If there is no spell being cast within 60' then you can't cast counterspell ... at least that is how RAW could be interpreted.

[CorporateSlave]

To do a basic summary: an invalid target does not mean that the spell is impossible to cast, just that it'll have no effect if cast, and that the absence of effect gives no direct clue as to why it failed.

Precisely, and well summarized.

To address the OP's question about spell casting fakery triggering Counterspell, by strict RAW, it would seem that since the spell description for Counterspell states: "...which you take when you see a creature within 60 feet of you casting a spell" I would say no, it probably wouldn't work to "fake out" someone, since it doesn't say anything like "when you think you see a creature with 60 feet of you casting a spell." (Maybe the Counterspell waits until the magical effect starts to form, and the Counterspeller senses the weave being manipulated? Who knows, as we've discussed - to the dismay of some - spell casting in 5e is really not broken down into steps so you can't really say at what part of spell casting Counterspell comes into play. Maybe the game-world logic regarding Subtle spell foiling Counterspell is that without the outward signs, it's too late by the time the caster detects the effect? Or maybe it is just the V, S, M that the Counterspeller detects and they could be tricked?)

However, if you have such a Bard and can convince your DM to house rule this, perhaps make that case that your Deception/Performance check against the caster's passive Arcana to see if you "trick" them? I would say using the above mechanic, Unoriginal's XGTE rules reference answers the rest of your questions - Counterspell is cast, Reaction used, spell slot consumed.

[NaughtyTiger]

If I may, Invalid Target is not Invalid Trigger, even Unoriginal conceded that point.

The PHB/XtgE do not discuss faking a spell can act as a magical trigger, it is silent on the matter. Some folks argue that if it isn't explicitly allowed in the rules, it isn't allowed by the rules.

That said, it is perfectly a reasonable ruling, not munchkining or cheating the system, and one that has been used in my games.

[Guy Lombard-O]

I'd rule it wouldn't work RAW just based on the wording of counterspell.

"Casting Time: I reaction, which you take when you see a creature within 60 feet of you casting a spell

You attempt to interrupt a creature in the process of casting a spell."

1) You have to see them - so counterspell isn't an option if blinded or unable to see.
2) They have to be within 60'
3) They have to be casting a spell (not pretending to cast a spell).

There is nothing in the description about "pretending" to cast a spell. There is no indication of the mechanics used to know that a spell is being cast or what that spell might be. However, the wording does require that there is actually a spell being cast ... however, this information is conveyed to the magic user with counterspell.

If you want to fluff it then simply say that casting a spell causes a disturbance in the weave that is visible to a magic user within 60' who is capable of casting counterspell. If subtle metamagic is being used then this effect is suppressed.

Someone pretending to cast a spell, no matter how good at it, would then simply not be harnessing any magic and this would be visible to the caster with counterspell.

I've never read (or heard) that magic is generally visible to casters. I think this is a really bad and dangerous idea, since it would logically apply to all sorts of things it shouldn't (seeing the magic on illusions and enchanted people/things, magical traps, probably a bunch of other things). As fluff, it seems like hitting a nail with a running chainsaw.

The pretend spell scenario seems like a case of specific/unusual rule trumping the general rule. Counterspell is intended for countering spells and allows people to do so, so that's how it's written. If they'd written it as "when you think you see a creature...casting a spell", it would sort of suggest to people that this whole pretending thing is something they should all look into, wouldn't it? As if the Devs were telling everyone that it was not only a legitimate strategy they can use, but actually suggesting that all players should think about it? Just because they didn't write the spell that way (possibly because it just didn't occur to them at the time?), doesn't mean it's disallowed simply because the spell's language doesn't specifically address the possibility.

Also, since it apparently takes a reaction to attempt to identify what spell the first caster is trying to cast that you might want to Counterspell, it doesn't seem likely that you can simply "tell" that the first caster might simply be pretending to cast a spell without using up your reaction (and therefore preventing you from casting a Counterspell anyhow). If it takes a moment/reaction to examine the caster's actions and determine what spell he's casting, then it would logically take a moment/reaction to examine the caster's actions enough to know he's faking it (assuming a decent performance).

[tieren]

To address the OP's question about spell casting fakery triggering Counterspell, by strict RAW, it would seem that since the spell description for Counterspell states: "...which you take when you see a creature within 60 feet of you casting a spell" I would say no, it probably wouldn't work to "fake out" someone, since it doesn't say anything like "when you think you see a creature with 60 feet of you casting a spell."

My problem with this argument, which is strong and valid RAW I concede, is that it leads to an absurd result.

We know from Subtle spell that casting can not be detected without noticing the spell components. Subtle casting does nothing to hide the "magicalness" of the casting other than remove those components.

We know Ready Action requires a "perceivable" circumstance to trigger.

Therefore it follows that the trigger for Counterspell is observing the components. I propose that the intended result is that Counterspell is triggered by the characters perception that a spell is being cast, and perception can be fooled (via deception) by someone mimicking the components but not actually casting a spell.

I believe this interpretation gives the RAI effect for counterspell, and social pillar investments like performance expertise, etc... at the same time.

It also prevents the use of spells as unofficial detectors (walking through a crowd trying to cast counterspell on everyone you see talking or gesturing in case they are trying to cast a spell at you unawares; or walking into every room and trying to cast eldritch blast on every object to see if there is a mimic present.)

[NaughtyTiger]

We know Ready Action requires a "perceivable" circumstance to trigger.

Therefore it follows that the trigger for Counterspell is observing the components.

As was incessantly pointed out in the "other" thread, Ready Action is not Counterspell.

You are proposing that there is no trigger when using a focus but there is with components. (Unoriginal's quote points out that a focus is triggerable)


It also prevents the use of spells as unofficial detectors (walking through a crowd trying to cast counterspell on everyone you see talking or gesturing in case they are trying to cast a spell at you unawares; or walking into every room and trying to cast eldritch blast on every object to see if there is a mimic present.)

It only prevents that IF you allow that you can fake casting a spell (action with deception check). Heck it only allows that IF you allow that any random gesture/work counts as faking a spell.

So it's a solution to a DM created problem.

[Unoriginal]

The rules on perceiving a spell being cast (also in the Xanathar's):


But what about the act of casting a spell? Is it possible for someone to perceive that a spell is being cast in their presence? To be perceptible, the casting ofa spell must involve a verbal, somatic, or material component. The form ofa material component doesn’t matter for the purposes of perception, whether it’s an object specified in the spell’s description, a component pouch, or a spellcasting focus.

If the need for a spell’s components has been removed by a special ability, such as the sorcerer’s Subtle Spell feature or the Innate Spellcasting trait possessed by many creatures, the casting of the spell is imperceptible. If an imperceptible casting produces a perceptible effect, it’s normally impossible to determine who cast the spell in the absence of other evidence.

There is no "caster automatically feels the Weave being interacted with" or the like in the rules. The casting of a spell is perceptible if its components are perceptible.

[tieren]

It only prevents that IF you allow that you can fake casting a spell (action with deception check). Heck it only allows that IF you allow that any random gesture/work counts as faking a spell.

So it's a solution to a DM created problem.

I see where you are coming from, if all casting is instantly automatically recognized as casting there is no need to try to detect it, you auto detect it.

In the crowd situation I was thinking of a magical ambush (arcane trickster ability) where the caster is hidden in the crowd and the background noise/hustle and bustle is enough for him to remain hidden while casting. "You walk through the crowded bazaar, there are dozens of people pressed close to you and all manner of haggling and arguments take place all around you. You see several strange men, 40 feet away, looking at you and saying something you can't hear, but you are confident they are not casting a spell at you because you find yourself trying but unable to cast counterspell."

With no ability to ever not be perceived casting, magical ambush would seem to be moot for any spell with a verbal component.

It is similar to the auto detection of invisible but not hidden creatures (a discussion I do not want to revisit)

[CorporateSlave]

There is no "caster automatically feels the Weave being interacted with" or the like in the rules. The casting of a spell is perceptible if its components are perceptible.

True, but the problem we start to run into here is that then by RAW, in that case shouldn't Counterspell be super easy to fake out by a skilled mimic with a spare component pouch? If all that matters is seeing the V, S, or M, then what actually connection to a spell being cast do they offer? Anybody can wave their hands, speak the words, and fling a heart of newt into the air with enough practice...but that doesn't necessarily mean they can cast the spell. But...Counterspell specifically states you see them casting a spell, not just that you think they are! So by RAW you both can and yet can't cast Counterspell against fakery.

This is precisely why I don't think it helps to read too deeply into the "real world" applications of the rules, and just accept and use them as written...or you end up in a logic loop:
1) Do you need to have V, S, or M to perceive casting a spell? Yes, per RAW.
2) Does Counterspell require require you to see a creature casting a spell? Yes, per RAW.
3) Can you "fake" casting a spell by mimicking the V, S, and/or M components? Well, I don't see why not...there is no other indication of casting taking place per RAW other than this.
4) So you could trick someone into Counterspelling a mimicked spell casting? Well, ok sure that follows...the only thing triggering the Counterspell Reaction is seeing a spell being cast, and the only elements of seeing a spell being cast are the V, S, and M components per RAW...
5) But doesn't the Counterspell description say "casts a spell" and the mimicking creature isn't actually casting anything so it shouldn't actually trigger the Reaction? Ah...crud. Also, yes per the RAW.

OK then DM, don't get into the complicated layer of describing what a wizard is doing and leave it to the players to decide if they think a spell is being cast or not, just say the wizard "casts a spell."

The RAW just wants to make clear that Counterspell can be used as a Reaction to interrupt a spell being cast...but that you need to be able to see the spell being cast for that to work, so here's how you can see it. I don't think they anticipated players picking it apart quite this much because in this case it falls into a loop.

[Millface]

This is one of those situations where I would never use this against one of my players, but if one of my players came up with it I'd roll with it.

You try to fake casting a spell to draw out a counter... you roll a deception check vs. my knowledge (arcana).

As far as objective truth goes though... it does seem to fall perfectly into the "invalid spell target" rules. You can cast counterspell on a doorknob, logic would indicate you could also cast it on someone pretending to cast a spell (it just wouldn't do anything).

How you want to describe and/or decide whether or not a PC or NPC falls for the charade is up to the DM. I'm inclined to think any caster of 5th level or higher is going to be pretty good at spotting fake vs. real magic being cast, but that's not explicitly stated.

I'm of a mind that this is exactly the kind of thing that Knowledge (Arcana) is for. In previous editions you could use its equivalent, spellcraft, to learn what spell was being cast before it was cast, seems like a sound leap in logic to assume we could play this the same way.

[jh12]

True, but the problem we start to run into here is that then by RAW, in that case shouldn't Counterspell be super easy to fake out by a skilled mimic with a spare component pouch? If all that matters is seeing the V, S, or M, then what actually connection to a spell being cast do they offer? Anybody can wave their hands, speak the words, and fling a heart of newt into the air with enough practice...but that doesn't necessarily mean they can cast the spell. But...Counterspell specifically states you see them casting a spell, not just that you think they are! So by RAW you both can and yet can't cast Counterspell against fakery.

If you can find a skilled mimic willing to go into combat situations and use their action pretending to cast spells, go for it. I'm guessing most skilled mimics can find more lucrative, and less dangerous, sources of income.

[JoeJ]

This is one of those situations where I would never use this against one of my players, but if one of my players came up with it I'd roll with it.

You try to fake casting a spell to draw out a counter... you roll a deception check vs. my knowledge (arcana).

As far as objective truth goes though... it does seem to fall perfectly into the "invalid spell target" rules. You can cast counterspell on a doorknob, logic would indicate you could also cast it on someone pretending to cast a spell (it just wouldn't do anything).

How you want to describe and/or decide whether or not a PC or NPC falls for the charade is up to the DM. I'm inclined to think any caster of 5th level or higher is going to be pretty good at spotting fake vs. real magic being cast, but that's not explicitly stated.

I'm of a mind that this is exactly the kind of thing that Knowledge (Arcana) is for. In previous editions you could use its equivalent, spellcraft, to learn what spell was being cast before it was cast, seems like a sound leap in logic to assume we could play this the same way.

This sounds reasonable to me as well. Counterspell, it seems to me, is intended to be a way to counter spells, not a way to infallibly detect them. A contest of Charisma (Deception) vs. Intelligence (Arcana) seems appropriate. A tie in a contest maintains the statue quo, which I think would be that the target does not believe the deception. (Of course, even if the deception works, the target might not choose to use Counterspell, but that's a separate issue.)

[Rukelnikov]

The simplest case is Invoke Duplicity.

Suppose Claire the Cleric uses that feature, and Walter the Wizard sees the illusion but not Claire. When Claire casts a spell, and doesn't choose to cast it thru her double, Walter is seeing someone within 60 ft of him casting a spell.

My understanding is that he can cast Counterspell, and he will lose the slot.

[Dalebert]

There's also the compromise position. You waste their reaction but not the spell slot for counterspell. Allow me to explain my reasoning. (Note: NOT arguing this is raw. Just a reasonable approach.)

Seeing them cast is a reqt to even know to CS. However, actual casting and interaction with the weave is necessary for CS to have something to interact with. Until that's there, your CS doesn't complete sufficiently for you to even expend the energy for spell casting.

This remains a viable strategy. The bard burning their reaction means the wizard or cleric now can't be CSed.

[tieren]

There's also the compromise position. You waste their reaction but not the spell slot for counterspell. Allow me to explain my reasoning. (Note: NOT arguing this is raw. Just a reasonable approach.)

Seeing them cast is a reqt to even know to CS. However, actual casting and interaction with the weave is necessary for CS to have something to interact with. Until that's there, your CS doesn't complete sufficiently for you to even expend the energy for spell casting.

This remains a viable strategy. The bard burning their reaction means the wizard or cleric now can't be CSed.

This is perfectly reasonable to me.


The simplest case is Invoke Duplicity.

Suppose Claire the Cleric uses that feature, and Walter the Wizard sees the illusion but not Claire. When Claire casts a spell, and doesn't choose to cast it thru her double, Walter is seeing someone within 60 ft of him casting a spell.

My understanding is that he can cast Counterspell, and he will lose the slot.

I'm glad you brought this up but I don't like the hypo the way you have phrased it. the Invoke Duplicity image isn't like mirror image, it is a perfect replica but it doesn't perfectly mimic your movements and what not (you can choose to move it or not etc...). So in your example you see an illusion and a caster somewhere else you can't see casts a spell, unless the cleric was making his illusion appear to be casting the spell I don't see why the character would cast counterspell on it.

The case I would like to consider is what if the cleric is 80 feet away and is casting a spell through the illusion which is only 40 feet away. The illusion is just standing there, not appearing to cast a spell, the cleric is visibly casting a spell but is out of counterspell range. Can the character effectively cast counterspell? Does it require him to know what invoke duplicity is and how it works?

[Rukelnikov]

I'm glad you brought this up but I don't like the hypo the way you have phrased it. the Invoke Duplicity image isn't like mirror image, it is a perfect replica but it doesn't perfectly mimic your movements and what not (you can choose to move it or not etc...). So in your example you see an illusion and a caster somewhere else you can't see casts a spell, unless the cleric was making his illusion appear to be casting the spell I don't see why the character would cast counterspell on it.

You are right, its not a Mirror Image, I just always pictured the double casting whenever a spell was cast thru it.


The case I would like to consider is what if the cleric is 80 feet away and is casting a spell through the illusion which is only 40 feet away. The illusion is just standing there, not appearing to cast a spell, the cleric is visibly casting a spell but is out of counterspell range. Can the character effectively cast counterspell? Does it require him to know what invoke duplicity is and how it works?

The feature says "For the duration, you can cast spells as though you were in the illusion's space, but you must use your own senses.", if you are making use of that option you are considered to be in the illusion's space, thus you can be countered.

[Unoriginal]

Counterspell is a rather powerful spell, you'll never know if the enemy caster has it before they cast, and you'll never know if they'll use it to counter a given spell rather than another.

Pretending to cast a spell to bait a counter, if ruled as possible, would be pretty risky or at least not that useful.


Unless you're fighting Josura the Spellbinder who is known to be particularly good at Counterspelling their opponents and used it as their main tactic to become such a famous magic duelist.

[tieren]

The feature says "For the duration, you can cast spells as though you were in the illusion's space, but you must use your own senses.", if you are making use of that option you are considered to be in the illusion's space, thus you can be countered.

Ah yes, BUT, counterspell says when you "see a creature casting a spell within 60 feet of you". In my scenario, even though the caster is effectively within range via the illusion, you do not see him casting a spell within range, you only see a stationary illusion within 60 feet of you and a caster casting a spell out of range.

What are you reacting to? Does counterspell require targeting or does it magically know where the spell is coming from?

[Keravath]

The rules on perceiving a spell being cast (also in the Xanathar's):



There is no "caster automatically feels the Weave being interacted with" or the like in the rules. The casting of a spell is perceptible if its components are perceptible.

No there isn't and I never suggested there was. I suggested "fluff" that could be used to explain why counterspell is ONLY triggered by "a creature within 60' casting a spell"

No where in the spell description does it indicate that you can trigger the casting of counterspell by simply believing that someone is casting a spell.

You come up with whatever mechanism you like to justify how it works RAW.

[tieren]

Counterspell is a rather powerful spell, you'll never know if the enemy caster has it before they cast, and you'll never know if they'll use it to counter a given spell rather than another.

Pretending to cast a spell to bait a counter, if ruled as possible, would be pretty risky or at least not that useful.


Unless you're fighting Josura the Spellbinder who is known to be particularly good at Counterspelling their opponents and used it as their main tactic to become such a famous magic duelist.

Clearly it won't become a common tactic in any event, but I thought of this scenario:

A traveling theater company trying to hide the fact it is chock full of full caster bards by having only one or two admit they can cast, but a dozen of their comrades constantly imitating them so the enemy doesn't know who the "true" casters are. Sort of an "I am Spartacus" situation.

[tieren]

No where in the spell description does it indicate that you can trigger the casting of counterspell by simply believing that someone is casting a spell.

You come up with whatever mechanism you like to justify how it works RAW.

No where in the spell description does it say you know when someone is casting a spell or when they aren't. We know it can be tricked when they are casting a spell by using Subtle to hide the fact. It doesn't seem an unreasonable assumption the other way.

[Unoriginal]

If a mage create the illusion of a summoned monster, and has it run next to an enemy combatant (who think the monster is real) and then leave their range, can the combatant use their AoO on the illusion?

RAW is silent on it. To me it's pretty obvious that if the combatant think the situation is X, and that it's possible to use Y in when the situation is X, then the combatant can use Y, even if it'll have no effect.

Same way that if a Rogue declares "I Ready an action to shoot the Rakshasa when he shows up" and that the Rakshasa has prepared five lesser minions disguised as him, it's more logical to have the Rogue's Ready action would trigger when the first thing they believe to be the Rakshasa shows up whether it's true or not than have the Rogue's Ready action bypass all disguise and only trigger when the actual one shows up.

[Man_Over_Game]

If a mage create the illusion of a summoned monster, and has it run next to an enemy combatant (who think the monster is real) and then leave their range, can the combatant use their AoO on the illusion?

RAW is silent on it. To me it's pretty obvious that if the combatant think the situation is X, and that it's possible to use Y in when the situation is X, then the combatant can use Y, even if it'll have no effect.

Same way that if a Rogue declares "I Ready an action to shoot the Rakshasa when he shows up" and that the Rakshasa has prepared five lesser minions disguised as him, it's more logical to have the Rogue's Ready action would trigger when the first thing they believe to be the Rakshasa shows up whether it's true or not than have the Rogue's Ready action bypass all disguise and only trigger when the actual one shows up.

I agree on this, for the most part. Just have it be that whenever a Reaction would be relevant, briefly describe the circumstance and let the player choose to spend their reaction, and how, at that particular time.

For the Illusion, the player has no reason to assume it's not a creature, so he'd act as if it was.

For the Rogue, I'd tell the Rogue at the time at the first possible moment of the trigger that he sees the Rakshasa...and several others behind him, and then ask what he'd do with his Reaction.

For Counterspell, the solution is just to not describe that they are "casting spells", but rather describe the casting and the effect as two separate things. "You see the mage stroke the large glass orb on his waste and mutter something too low to hear. Immediately after, lightning arcs from the orb and launches straight for the Barbarian." This solves any problem anyone would ever have with determining how Counterspell works.

I don't think that outside influence should really determine much as to how a player should be able to spend their Reaction if it's to prevent something. If a player wants to cast Counterspell when the creature isn't casting a spell, go for it. On the flipside, don't let players be able to freely spend their Reaction for proactive benefits, like Opportunity Attacks or Hellish Rebuke, and everything will be fine.

[Rukelnikov]

Ah yes, BUT, counterspell says when you "see a creature casting a spell within 60 feet of you". In my scenario, even though the caster is effectively within range via the illusion, you do not see him casting a spell within range, you only see a stationary illusion within 60 feet of you and a caster casting a spell out of range.

What are you reacting to? Does counterspell require targeting or does it magically know where the spell is coming from?

Well, I interpret "as though you were" as "for all intents and purposes regarding this particular cast of a spell you effectively are in that square". So yeah, you would be able to counterspell it, the cleric may actually be 80 ft. from the wizard, but he counts as only being 40 ft away.

Now, if the Wizard CAN'T see the cleric, thing is different...

If the image is still, then Wizard doesn't see anyone casting a spell and can't counter.

If the image mimics the casting, then Wizard sees someone casting a spell and can attempt counter.

While RAW it doesn't say the image moves at all, I'm pretty sure it does, considering:

"Additionally, when both you and your illusion are within 5 feet of a creature that can see the illusion, you have advantage on attack rolls against that creature, given how distracting the illusion is to the target."

If it was just a Silent Image of you, it wouldn't be distracting at all.

[NaughtyTiger]

The simplest case is Invoke Duplicity..

I don't see that as related, nor as a good example for counterspell targets.
if it was difficult to tell the real you from the dup image, then it should cause disadvantage on attacks against you, right?



For the duration, you can cast spells as though you were in the illusion's space, but you must use your own senses.
Additionally, when both you and your illusion are within 5 feet of a creature that can see the illusion, you have advantage on attack rolls against that creature, given how distracting the illusion is to the target.

It can explicitly do this:
you can cast spells as though you are in its space.
your melee attacks have advantage



Well, I interpret "as though you were" as "for all intents and purposes regarding this particular cast of a spell you effectively are in that square". So yeah, you would be able to counterspell it, the cleric may actually be 80 ft. from the wizard, but he counts as only being 40 ft away.

I was all ready to dismiss this, but I see that as a valid interpretation. Hadn't thought of that.


on the other hand, silent image CAN move

[Rukelnikov]

I don't see that as related, nor as a good example for counterspell targets.
if it was difficult to tell the real you from the dup image, then it should cause disadvantage on attacks against you, right?

It's a perfect illusion of yourself, of course its difficult to tell the real from the image. I don't see though, why would that cause disadv.



It can explicitly do this:
you can cast spells as though you are in its space.
your melee attacks have advantage

I know... I listed those features...


on the other hand, silent image CAN move

True I was thinking Minor Illusion

[Man_Over_Game]

It can explicitly do this:
you can cast spells as though you are in its space.
your melee attacks have advantage


You just made me realize I could do something interesting:

Use Polearm.
Have Illusion stand 10-15 feet away.
Cast Booming Blade with Illusion with Advantage.
Eventually get War Caster and Polearm Master to make this a thing.

The only real problem is that Booming Blade isn't a Cleric cantrip. Might have to go Fighter 4 for Heavy Armor, cantrips, and Shield to make it all work right. A bit expensive, but still cool.

[Rukelnikov]

You just made me realize I could do something interesting:

Use Polearm.
Have Illusion stand 10-15 feet away.
Cast Booming Blade with Illusion with Advantage.
Eventually get War Caster and Polearm Master to make this a thing.

The only real problem is that Booming Blade isn't a Cleric cantrip. Might have to go Fighter 4 for Heavy Armor, cantrips, and Shield to make it all work right. A bit expensive, but still cool.

"both you and your illusion are within 5 feet of a creature that can see the illusion"

[Man_Over_Game]

"both you and your illusion are within 5 feet of a creature that can see the illusion"

And this is why we can't have nice things, you (Russian?) bastard.

[Rukelnikov]

And this is why we can't have nice things, you (Russian?) bastard.

Ahahaha

Nah, I'm Argentinian, but that's been my Nick for like 20 yrs now

[Man_Over_Game]

I guess you could do the same thing with a close-ranged weapon, though. It'd be less cool.

Eldritch Knight X, Trickery Cleric 2. Action Surge GWM Booming Blade with Advantage, for tons of damage.

[Rukelnikov]

I guess you could do the same thing with a close-ranged weapon, though. It'd be less cool.

Eldritch Knight X, Trickery Cleric 2. Action Surge GWM Booming Blade with Advantage, for tons of damage.

Less cool for sure, you could be an elf otherwise or take MI

[greenstone]

Casting a spell must be perceptible, otherwise features like counterspell and mage slayer could not exist.

There must be something about casting magic that is immediately obvious, otherwise you could never know when to counterspell until the fireball or disintegrate actually hits you (at which time it is too late). It must, in addition, be visible, because you can counterspell in silence but not in darkness.

In my D&D games, I rule that spellcasting is perceptible and obvious to everyone. The somatic gestures leave trails of visual effects (Dr Strange from the Marvel movies). The vocalised sounds have an echo or reverb that is impossible for a normal voice to make.

Spellcasting can't be hidden, but it also can't be faked.

Spellcasting is also very fast. This is why normal reactions always happen after the casting is finished (e.g. Ready Action) and you need special training (counterspell, shield) to be able to interrupt a spell before the casting is finished.

[NaughtyTiger]

It's a perfect illusion of yourself, of course its difficult to tell the real from the image.
no it isn't unless the DM says it is.
perfect illusion doesn't specify any additional benefits than what it specifies.


I don't see though, why would that cause disadv.

i don't see why "perfect illusion" is enough to trigger on a false target for counterspell but not hamper an attack against you in anyway...
since you listed the features, you also should note that false trigger ain't amongst them.



Spellcasting is also very fast. This is why normal reactions always happen after the casting is finished (e.g. Ready Action) and you need special training (counterspell, shield) to be able to interrupt a spell before the casting is finished.

wrong thread for this one, there is a pointless and heated thread over here http://www.giantitp.com/forums/showthread.php?583570-What-ways-are-there-to-disrupt-spellcasting-in-5e

[Unoriginal]

Casting a spell must be perceptible, otherwise features like counterspell and mage slayer could not exist.

There must be something about casting magic that is immediately obvious, otherwise you could never know when to counterspell until the fireball or disintegrate actually hits you (at which time it is too late). It must, in addition, be visible, because you can counterspell in silence but not in darkness.

See the rules on perceiving casting. You perceive the spell's components, not the spell itself.

[CorporateSlave]

See the rules on perceiving casting. You perceive the spell's components, not the spell itself.

I think what he is saying is although it is the components that are perceived, there is (at his table at least) something particular about the components that make them distinguishable as being part of a cast spell rather than mundane use of the same thing. (i.e. a charlatan waving his arms may be in the same pattern as a wizard, but when the wizard casts a spell there is some light trail, or air disturbance, or something else that makes it obvious "this is a V/S/M component of a spell being cast and not just an old man shaking his fist at the sky and throwing a heart of newt at you."

Nothing specific in the RAW about this, but it makes a fairly reasonable in game explanation.