Complicated spell interaction

[Iliumin]

Ok, so I recently asked this question over at the SIMPLE RAW thread (http://www.giantitp.com/forums/showthread.php?561952-Simple-RAW-for-5e-4-Smackdown-v-RAW/page21) and the answer came back as unclear, so I'm opening this topic to discuss it further.

Here's what happened: We had an Ambition Domain (http://dnd5e.wikidot.com/cleric:ambition) cleric with Invoke Duplicity.
Starting at 2nd level, you can use your Channel Divinity to create an illusory duplicate of yourself.

As an action, you create a perfect illusion of yourself that lasts for 1 minute, or until you lose your concentration (as if you were concentrating on a spell). The illusion appears in an unoccupied space that you can see within 30 feet of you. As a bonus action on your turn, you can move the illusion up to 30 feet to a space you can see, but it must remain within 120 feet of you.

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.

At some point during a fight the cleric found himself in an Antimagic Field (https://roll20.net/compendium/dnd5e/Antimagic%20Field#content), but the illusion is NOT in that field, and the question came up: can he use the illusion to cast a spell such as Dimension Door (https://roll20.net/compendium/dnd5e/Dimension%20Door#content) (which has a range of self and normally would not work inside of an anti-magic field) in order to teleport out of the anti-magic field?

I am DM'ing the game and I say RAW seems to indicate yes because of the ability to "cast as if you were in the illusion's space", but RAI are a little unclear. It was our final fight of the evening anyway, so I left the group in suspense and am trying to do some research so I can give a fair answer. Any thoughts?

[Throne12]

No because that magic is coming from the caster.

[Mellack]

I would say no because the effect they want is inside the zone. Now they can DD the duplicate to my mind. The effect would be as if done in the duplicate's space, counting the duplicate as the caster.

[Unoriginal]

You can't use a magic power when you're in an Antimagic Field. If a Trickery Cleric steps in an AMF while their illusion stays outside, the illusion disappears. Or arguable it stays still but cannot be controlled by the caster.

[Iliumin]

Ok, so there seems to be a "no, not allowed" consensus, but with different interpretations of what is allowed. Any consensus on this point?


No because that magic is coming from the caster.
Throne12 says no because the magic is emanating from the caster, not the duplicate.


I would say no because the effect they want is inside the zone. Now they can DD the duplicate to my mind. The effect would be as if done in the duplicate's space, counting the duplicate as the caster.
Mellack says no for what appears to be the same reason, but indicates that the duplicate can cast the DD on itself, implying that the duplicate is capable of generating it's own magic.


You can't use a magic power when you're in an Antimagic Field. If a Trickery Cleric steps in an AMF while their illusion stays outside, the illusion disappears. Or arguable it stays still but cannot be controlled by the caster.
Unoriginal says no, but seems to indicate that the illusions are sustained by magic from the caster continuously, or at least that control over them is a continuous magical effect.

[Throne12]

My answer ties with unoriginal's it I just couldn't type out a long response. I was stuck in a trailer with a hourse.

[Derpy]

Even if the illusion can cast dimension door the text of anti-magic is pretty clear, to me at least, "Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can’t protrude into it." Furthermore; "Magical Travel. Teleportation and planar travel fail to work in the sphere, whether the sphere is the destination or the departure point for such magical travel. A portal to another location, world, or plane of existence, as well as an opening to an extradimensional space such as that created by the rope trick spell, temporarily closes while in the sphere." Therefore, you cant dimension door into or out of the area of a anti-magic field regardless of where the spell is cast from, RAW.

If I was feeling really snarky, I'd say sure you can cast (or attempt to cast) dimension door. Now you are out a 4th level spell slot. Do you wish to do anything else on your turn? "A slot expended to cast a suppressed spell is consumed" per anti-magic spell description. Therefore it's possible to try and will cost to try, even if it does not succeed.

[Ultimate_Coffee]

RAW gives no indication that the illusory duplicate created by Invoke Duplicity is a magical effect (although logic would imply that it must be.) Because of this, it should be possible to keep and control your duplicate, even while you are both within the antimagic field. Logic indicates that the duplicate is a magical effect however, so your duplicate should be suppressed while within the field. You would still be able to control your duplicate if he was out of the field however... Nothing in the antimagic field spell indicates that you cannot interact with your own magical effects that exist outside the field.

Based on this, yes, your caster should be able to cast spells while within the field, as long as his duplicate is outside, because Invoke Duplicity says
For the duration, you can cast spells as though you were in the illusion’s space.

The specific scenario of teleporting out of the antimagic field however, still would not work. The antimagic field spell says, on Magical Travel,
Teleportation and planar travel fail to work in the sphere, whether the sphere is the destination or the departure point for such magical travel. Bolded for emphasis.

You are casting the spell as if you were in the duplicate's space, but the effect of the spell would still be teleporting you, and the departure point for that teleportation (you) is still within the antimagic sphere. So, despite being able to cast spells from within the antimagic field, you cannot use these spells to teleport yourself out of the field.

Or... you know... do what's fun... ^_^

[Keravath]

I'd agree with the other posters.

The antimagic field doesn't break concentration and so it would not prevent the functioning of the illusory duplicate. It also wouldn't affect spells currently active outside the antimagic field or any spells cast outside onto targets outside.

However, the antimagic field is very specific that magic doesn't function inside the field.

"Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can't protrude into it."

"Teleportation and planar travel fail to work in the sphere, whether the sphere is the destination or the departure point for such magical travel."

So there is no way the dimension door spell could remove the character from the antimagic field even if the character was able to cast it.

"A slot expended to cast a suppressed spell is consumed."

The dimension door spell would be suppressed but the spell slot would be lost in any case.

[Throne12]

Oh and sometime to point out. It say YOU cast spells as if your where there. So you are casting a spell and if you are in a anti-magic area you cant cast spells.

[Ultimate_Coffee]

Oh and sometime to point out. It say YOU cast spells as if your where there. So you are casting a spell and if you are in a anti-magic area you cant cast spells.

Interestingly, Antimagic Field doesn't say YOU can't cant spells. What is says is
Within the sphere, spells can’t be cast

So, if you are casting the spell from the duplicates space, you are okay to do so...

[Laserlight]

At some point during a fight the cleric found himself in an Antimagic Field (https://roll20.net/compendium/dnd5e/Antimagic%20Field#content), but the illusion is NOT in that field, and the question came up: can he use the illusion to cast a spell such as Dimension Door (https://roll20.net/compendium/dnd5e/Dimension%20Door#content) (which has a range of self and normally would not work inside of an anti-magic field) in order to teleport out of the anti-magic field?

Two parts.
1. Can the illusion cast anything at all? I think that is subject to argument, but I'd probably rule Yes based on Rule of Cool.
2. Can DimDoor affect the Cleric inside the AMF? I think that's a definite No.

[Derpy]

Interestingly, Antimagic Field doesn't say YOU can't cant spells. What is says is

So, if you are casting the spell from the duplicates space, you are okay to do so...

You are casting as though you were in the illusion's space. You are not casting from the illusions space, but only as though you were. An illusion, if you will, of where it is being cast from. it is a fine distinction, but I think that means RAW, if you're in anti-magic you cant cast (or rather you can, but the spell's effects are suppressed). <-Edited out my thought on that.


Two parts.
1. Can the illusion cast anything at all? I think that is subject to argument, but I'd probably rule Yes based on Rule of Cool.

Invoke Duplicity clearly says the player is casting, not the illusion. RAW on that, at least, seems very clear.

[Iliumin]

Thank you all for the responses! Seems to be a consensus that:
1) The magic is emanating from the player, not the illusion, and therefore no spells can be [successfully] cast (though it was suggested to possibly allow it for fun purposes), though they may be attempted and spell slots burned.
2) DD absolutely cannot be cast into or out of an Anti-Magic Field, even if the magic is coming from outside of it.
3) The illusion is suppressed if it should find itself to be in the Anti-Magic Field at some point in the future.

[Kupursk]

"or until you lose your concentration (as if you were concentrating on a spell)."

In my opinion this pretty much settles the fact that the illusion shouldn't even work if the caster is inside an Antimagic Shell, which is what I would have ruled anyway, personally.

When inside an Antimagic Shell your caster is basically a non-caster and can't do anything caster related. If the illusion requires concentration as if it were a spell, it mainly works as a spell. Which seems to be the general idea with domain powers.

Edit: But honestly you should allow narrative decide instead of "raw" rules. Consider how you think magic works in your world, would the illusion have a pseudo-life of its own, or would the caster need "invisible magic strings" tying him to the copy, which are broken when he enters the Antimagic zone. Magic isn't real anyway, so whatever fits your own notion of how it'd work is fine.

[Man_Over_Game]

"or until you lose your concentration (as if you were concentrating on a spell)."

In my opinion this pretty much settles the fact that the illusion shouldn't even work if the caster is inside an Antimagic Shell, which is what I would have ruled anyway, personally.

When inside an Antimagic Shell your caster is basically a non-caster and can't do anything caster related. If the illusion requires concentration as if it were a spell, it mainly works as a spell. Which seems to be the general idea with domain powers.

Edit: But honestly you should allow narrative decide instead of "raw" rules. Consider how you think magic works in your world, would the illusion have a pseudo-life of its own, or would the caster need "invisible magic strings" tying him to the copy, which are broken when he enters the Antimagic zone. Magic isn't real anyway, so whatever fits your own notion of how it'd work is fine.

Here's the official Sage Advice on what's magical:

Determining whether a game feature is magical is straightforward. Ask yourself these questions about the feature:
•Is it a magic item?
•Is it a spell? Or does it let you create the effects of a spell that’s mentioned in its description?
•Is it a spell attack?
•Is it fueled by the use of spell slots?
•Does its description say it’s magical?

If your answer to any of those questions is yes, the feature is magical.

Let’s look at a white dragon’s Cold Breath and ask ourselves those questions. First, Cold Breath isn’t a magic item. Second, its description mentions no spell. Third, it’s not a spell attack. Fourth, the word “magical” appears nowhere in its description. Our conclusion: Cold Breath is not considered a magical game effect, even though we know that dragons are amazing, supernatural beings.


Additionally, Anti-Magic Field says:

"Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can't protrude into it."

Lastly, from PHB p.52, regarding Channel Divinity:

At 2nd level, you gain the ability to channel divine energy directly from your deity[..]

So:

Channel Divinity: Invoke Duplicity is not magical, RAW.
If Channel Divinity WAS magical as a narrative choice, then the same narrative would fit that it was directly from a diety, and magical effects from deities ignore Anti-Magic Field.


Whether or not the illusion is capable of casting spells while you're in the AMF is pretty open ended, but the illusion should work as a standalone object regardless of the AMF.

[Derpy]

Here's the official Sage Advice on what's magical:


Additionally, Anti-Magic Field says:


Lastly, from PHB p.52, regarding Channel Divinity:


So:

Channel Divinity: Invoke Duplicity is not magical, RAW.
If Channel Divinity WAS magical as a narrative choice, then the same narrative would fit that it was directly from a diety, and magical effects from deities ignore Anti-Magic Field.


Whether or not the illusion is capable of casting spells while you're in the AMF is pretty open ended, but the illusion should work as a standalone object regardless of the AMF.

So, would you argue that because, according to the PHB, "As a conduit for divine power, you can cast cleric spells." that anti-magic field would not effect a cleric casting regardless? Or paladins; "By 2nd level, you have learned to draw on divine magic through meditation and prayer to cast spells as a cleric does."

Also, it's still explicitly written that the player is casting, not the illusion, it's not 'open ended.'

And, like other people said, don't take any debate to mean not to do what is fun in your game; that's the main goal!

[CorporateSlave]

"or until you lose your concentration (as if you were concentrating on a spell)."

In my opinion this pretty much settles the fact that the illusion shouldn't even work if the caster is inside an Antimagic Shell, which is what I would have ruled anyway, personally.

When inside an Antimagic Shell your caster is basically a non-caster and can't do anything caster related. If the illusion requires concentration as if it were a spell, it mainly works as a spell. Which seems to be the general idea with domain powers.

Edit: But honestly you should allow narrative decide instead of "raw" rules. Consider how you think magic works in your world, would the illusion have a pseudo-life of its own, or would the caster need "invisible magic strings" tying him to the copy, which are broken when he enters the Antimagic zone. Magic isn't real anyway, so whatever fits your own notion of how it'd work is fine.

Having the illusion fade out seems excessive to me, as long as it remains outside the Antimagic Field. Without getting into the "real world" reasoning behind this, RAW - the spell description for Antimagic Field makes a lot of detailed and explicit statements about what effects the Field counters/suppresses and how that works. It says nothing about breaking Concentration. Many spell effects require Concentration but have nothing to do with the location of the caster after the spell is cast. RAW, if the effect of the illusion is outside the Field, it would remain. Being inside an Antimagic Field that cancelled out all external Concentration effects if the caster happened to find themselves inside the Field would be a relatively major effect (Haste, Invisibility, etc cast on other PC or NPC), and ought to have been listed in the spell description as a specific effect of the Field.

There is nothing in the RAW descriptions of Concentration that I can find that makes me think Concentration creates some magical link between the caster and the target which would be subject to being broken by an Antimagic Field. Or, if you prefer "real world" reasoning, just as one can see the non-suppressed effects of a wall of fire outside the Field, one can continue to Concentrate on the magic pattern of a spell when the effect is outside the Field area. Now, if the RAW for Concentration mentioned that the pattern of the magic is located in the caster's head, and projects outward to the final effect, that might be a different story.

Here is perhaps the best way to look at it: Antimagic Field itself requires Concentration, and per the spell description remains centered on the caster! How could Concentration be broken within the Field if the Field requires Concentration? (Based on the OP's description, I imagine that the Cleric is inside some other Wizard's Antimagic Shell?)

Of course, the DM's call ought to be law based on what he/she thinks works best for the story.

[Man_Over_Game]

So, would you argue that because, according to the PHB, "As a conduit for divine power, you can cast cleric spells." that anti-magic field would not effect a cleric casting regardless? Or paladins; "By 2nd level, you have learned to draw on divine magic through meditation and prayer to cast spells as a cleric does."

Also, it's still explicitly written that the player is casting, not the illusion, it's not 'open ended.'

Your quote says "As a conduit for divine power, you can cast cleric spells.", however Channel Divinity says "you gain the ability to channel divine energy directly from your deity", and Anti Magic Field says "Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can't protrude into it."

Sure, it's reading between the lines (and isn't that what this thread is about?), but it seems like casting magic comes from the Cleric's abilities, but casting Channel Divinity comes "directly from your deity".

Paladins don't have a deity, and the 2nd level feature refers to their ability to "cast spells as a Cleric does", and I'd argue that a Cleric's spellcasting is their own.

If a special case has to be made to identify Invoke Duplicity as magical (despite having no facts to defend this), then I also argue that special case is deserved to be made that Channel Divinity is exempt from Anti-Magic Field, if only due to the clause in Channel Divinity and Anti-magic field related to deities.

----------

I agree that the player is casting, but the Invoke Duplicity also explictly states that the character "can cast spells as though you were in the illusion’s space."

So what has more precedence? The fact that AMF says you cannot cast a spell, or the fact that Invoke Duplicity says you can? That seems pretty open-ended to me.

[Derpy]

Your quote says "As a conduit for divine power, you can cast cleric spells.", however Channel Divinity says "you gain the ability to channel divine energy directly from your deity", and Anti Magic Field says "Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can't protrude into it."

Sure, it's reading between the lines (and isn't that what this thread is about?), but it seems like casting magic comes from the Cleric's abilities, but casting Channel Divinity comes "directly from your deity".

Paladins don't have a deity, and the 2nd level feature refers to their ability to "cast spells as a Cleric does", and I'd argue that a Cleric's spellcasting is their own.

If a special case has to be made to identify Invoke Duplicity as magical (despite having no facts to defend this), then I also argue that special case is deserved to be made that Channel Divinity is exempt from Anti-Magic Field, if only due to the clause in Channel Divinity and Anti-magic field related to deities.

----------

I agree that the player is casting, but the Invoke Duplicity also explictly states that the character "can cast spells as though you were in the illusion’s space."

So what has more precedence? The fact that AMF says you cannot cast a spell, or the fact that Invoke Duplicity says you can? That seems pretty open-ended to me.

Once again, we read between the lines; you can cast as though you were in the illusions space, but you cannot cast from the illusions space. You know, like an illusion. What good would an illusion like that be if everything appeared to come from one source? If the person who wrote the rules wanted a caster to cast from the illusion's space they would have written you can cast from the illusions space, not as though you were in the illusion's space. Precise wording is important here, like it is for the source of the illusion. It is a fine distinction, but it is a similar distinction.

A relevant point about the illusion itself, I missed the important wording on that.

[Iliumin]

you can cast as though you were in the illusions space, but you cannot cast from the illusions space. Precise wording is important here, like it is for the source of the illusion. It is a fine distinction, but it is a similar distinction.


I apologize, but I'm not seeing the difference. Those two statements seem grammatically and functionally equivalent to me. Are you saying that spell ranges and such cannot be extended by the range of the illusion (eg: casting a 20' range spell as though you were in the illusion's space, 100' away)?

[Man_Over_Game]

I apologize, but I'm not seeing the difference. Those two statements seem grammatically and functionally equivalent to me. Are you saying that spell ranges and such cannot be extended by the range of the illusion (eg: casting a 20' range spell as though you were in the illusion's space, 100' away)?

One of the definitions implies a copycat, a mimicry, a duplicate. The other definition implies it's the real thing.

Similarly, there was a misprint version of the Arcane Archer Fighter subclass, which read something like "You can fire your arrows as if they were magical for the purposes of overcoming resistances and immunity", but were not technically magical. This was important, because the Arcane Archer was written to also require magic arrows for its enhanced shot abilities. Combined, this meant the Arcane Archer couldn't technically use its own features to fire enhanced arrows, but they fixed this shortly after Xanathar's was released.

He's saying that you're acting as though you're casting in the illusion's space, but technically casting from your own, and you must be able to cast from your own space to use your illusion's. I think.

[Derpy]

I apologize, but I'm not seeing the difference. Those two statements seem grammatically and functionally equivalent to me. Are you saying that spell ranges and such cannot be extended by the range of the illusion (eg: casting a 20' range spell as though you were in the illusion's space, 100' away)?

https://dictionary.cambridge.org/us/grammar/british-grammar/as-and-as-expressions/as-if-and-as-though
quoted "We use as if and as though to make comparisons. They have a similar meaning. We use as if and as though to talk about an imaginary situation or a situation that may not be true but that is likely or possible."

The language used in the PHB does not use a definitive term, as in 'you are casting from the illusion's space' and instead uses a term that invokes that the illusion is doing just that, being a convincing and hard to differentiate but insubstantial thing. While it is not possible for the illusion to cast, it is likely that it will be perceived as such, in order to keep the illusion being convincing.

Think about a phrase like, "he ran as though the hounds of hell were after him." Now, it does not mean that hounds of hell are chasing someone (D&D backdrop to this linguistic discourse notwithstanding) but that it creates the appearance of something that might be likely to our minds to give us a context of how fast the person is going.

[Ganymede]

"Determining whether a game feature is magical is straightforward. Ask yourself these questions about the feature:
• Is it a magic item?
• Is it a spell? Or does it let you create the effects of a spell that’s mentioned in its description?
• Is it a spell attack?
• Is it fueled by the use of spell slots?
• Does its description say it’s magical?"

Bolded for emphasis.


Channel Divinity - "At 2nd level, you gain the ability to channel divine energy directly from your deity, using that energy to fuel magical effects."

Bolded for emphasis.

It looks like the question is moot because the Duplicate would be suppressed as soon as the Cleric entered the antimagic field, or at least the ability to control or utilize the Duplicate would be suppressed, as per Crawford.

[Man_Over_Game]

https://dictionary.cambridge.org/us/grammar/british-grammar/as-and-as-expressions/as-if-and-as-though
quoted "We use as if and as though to make comparisons. They have a similar meaning. We use as if and as though to talk about an imaginary situation or a situation that may not be true but that is likely or possible."

The language used in the PHB does not use a definitive term, as in 'you are casting from the illusion's space' and instead uses a term that invokes that the illusion is doing just that, being a convincing and hard to differentiate but insubstantial thing. While it is not possible for the illusion to cast, it is likely that it will be perceived as such, in order to keep the illusion being convincing.

Think about a phrase like, "he ran as though the hounds of hell were after him." Now, it does not mean that hounds of hell are chasing someone (D&D backdrop to this linguistic discourse notwithstanding) but that it creates the appearance of something that might be likely to our minds to give us a context of how fast the person is going.

I guess my counterpoint is, what's the difference?

If being able to cast a spell as though they were in the illusion's space allows them some benefits but not others, where is the line drawn? If the caster is out of range for a spell, but the illusion is not, they are able to cast a spell despite the standard rules not allowing it to be possible. The illusion already allows exceptions. But there's no defining line as to where those exceptions end, where it seems that you're stating that they do.

I'm under the opinion that there isn't a line drawn. Every exception that could be made from casting from the Illusion's space should be made, otherwise it kinda just feels like we're just guessing and making stuff up.

[Derpy]

I guess my counterpoint is, what's the difference?

If being able to cast a spell as though they were in the illusion's space allows them some benefits but not others, where is the line drawn? If the caster is out of range for a spell, but the illusion is not, they are able to cast a spell despite the standard rules not allowing it to be possible. The illusion already allows exceptions. But there's no defining line as to where those exceptions end, where it seems that you're stating that they do.

I'm under the opinion that there isn't a line drawn. Every exception that could be made from casting from the Illusion's space should be made, otherwise it kinda just feels like we're just guessing and making stuff up.

The difference the the illusion is not casting. nothing is coming from the illusion, other then illusion. Everything is coming from the caster, but only appearing as though it was coming from the illusion. it does not let you cast further, cast around corner, or cast outside an anti-magic field. You, the caster are casting. You have the choice of making it look like you are casting, or as though the illusion was casting. It grants no other RAW benefits as far as I can see.

[Man_Over_Game]

The difference the the illusion is not casting. nothing is coming from the illusion, other then illusion. Everything is coming from the caster, but only appearing as though it was coming from the illusion. it does not let you cast further, cast around corner, or cast outside an anti-magic field. You, the caster are casting. You have the choice of making it look like you are casting, or as though the illusion was casting. It grants no other RAW benefits as far as I can see.

There is this little bit:

For the duration, you can cast spells as though you were in the illusion’s space, but you must use your own senses. If it were implied that you were casting the spell from your own space, then I'd say it'd be a bit redundant to require you to use your own senses.

"You can cast a spell from your space and use illusion magic to make it appear as if it were from another space, but you must use your own senses to do so" doesn't seem like an accurate interpretation to me. Additionally, unlike Mirror Image, it doesn't have any mentioned benefits as to what a "perfect illusion" does, or what casting a spell from a different space provides for you (when something like the Arcane Trickster provides Disadvantage on Saving Throws when casting while hidden).

I think you're the outlier with your interpretation. Most would assume that Invoke Duplicity means that, for all intents and purposes, you can cast spells as though you were using the Illusion's space, including things like ranges or target designation, as long as the real character can see the target.

[Keravath]

The difference the the illusion is not casting. nothing is coming from the illusion, other then illusion. Everything is coming from the caster, but only appearing as though it was coming from the illusion. it does not let you cast further, cast around corner, or cast outside an anti-magic field. You, the caster are casting. You have the choice of making it look like you are casting, or as though the illusion was casting. It grants no other RAW benefits as far as I can see.

The specific channel divinity states the following:

"For the duration, you can cast spells as though you were in the illusion’s space, but you must use your own senses."

It states "you can cast spells as though you were in the illusions's space". This does NOT state, "the spells you cast appear to come from the illusion's space" as you seem to suggest.

This means that if the illusion is 100' away, you could cast healing word within its 60' range of the illusion up to 160' from your current location. However, you have to use your own senses to do so, thus you need to be able to see your target directly even if it is 160' away.

However, this also means that the point of origin of the spell IS the illusion. The cleric is casting the spell but the point of origin for the spell is the illusion. The cleric could cast thunderwave or thorn whip from the location of the illusion for example and could affect and target creatures near the illusion with these spells, up to 120' from the cleric's current position, assuming the cleric can see the target themselves.

[Derpy]

There is this little bit:
If it were implied that you were casting the spell from your own space, then I'd say it'd be a bit redundant to require you to use your own senses.

"You can cast a spell from your space and use illusion magic to make it appear as if it were from another space, but you must use your own senses to do so" doesn't seem like an accurate interpretation to me. Additionally, unlike Mirror Image, it doesn't have any mentioned benefits as to what a "perfect illusion" does, or what casting a spell from a different space provides for you (when something like the Arcane Trickster provides Disadvantage on Saving Throws when casting while hidden).

I think you're the outlier with your interpretation. Most would assume that Invoke Duplicity means that, for all intents and purposes, you can cast spells as though you were using the Illusion's space, including things like ranges or target designation, as long as the real character can see the target.

I am sure I'm an outlier in my interpretation, I don't think it makes the wording any less grammatically in my favor. It does have a mentioned benefit to what this perfect illusion does. The last sentence in the ability "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." In addition, unlike many illusion spells, there is no mention of physical interaction reveling it to be an illusion (or any way at all to find out, though personally i'd let something like detect magic do the trick) which is a huge benefit in it's own right. I'm not 100% sure how that'd work out mechanically in combat, however.

That aside, and with a bit more research; https://www.sageadvice.eu/2018/03/28/__trashed-10/ ; makes me think that the illusion is, or at least seems to be, intended for things like increased range. I think they could have used more precise terminology but this is hardly the only thing they could have been clearer on the wording (JC even being a bit cagey in his response, but there is a character limit on twitter). You have to be within 60' of the caster, but seeing the illusion itself seems to be enough as long as your within that range. That's pretty convoluted, IMO.

Also, however, things like this https://www.sageadvice.eu/2016/05/29/if-a-cleric-has-invoke-duplicity-on-and-is-restrined-can-cast-from-the-image/ coupled with the within 60' of the caster for counter spell from the previous SA, still has me pretty sure the original source of the spell is the caster, who is still in anti-magic in the OP. Though, that seems to be a less debated issue.

[Iliumin]

The specific channel divinity states the following:

"For the duration, you can cast spells as though you were in the illusion’s space, but you must use your own senses."

It states "you can cast spells as though you were in the illusions's space". This does NOT state, "the spells you cast appear to come from the illusion's space" as you seem to suggest.

This means that if the illusion is 100' away, you could cast healing word within its 60' range of the illusion up to 160' from your current location. However, you have to use your own senses to do so, thus you need to be able to see your target directly even if it is 160' away.

However, this also means that the point of origin of the spell IS the illusion. The cleric is casting the spell but the point of origin for the spell is the illusion. The cleric could cast thunderwave or thorn whip from the location of the illusion for example and could affect and target creatures near the illusion with these spells, up to 120' from the cleric's current position, assuming the cleric can see the target themselves.

This is exactly the interpretation I had as well, and I was allowing the cleric to extend their spells in this manner.

This also means that someone with the Mage Slayer feat (https://dnd5e.fandom.com/wiki/Feats#Mage_Slayer) can use their reaction to attack the cleric, even though the illusion is the point of origin. Because it's the cleric themselves who are casting the spell. This interpretation seems consistent with how the spell is intended to work and is consistent with the ruling on the Anti-Magic Field.

EDIT:


That aside, and with a bit more research; https://www.sageadvice.eu/2018/03/28/__trashed-10/ ; makes me think that the illusion is, or at least seems to be, intended for things like increased range. I think they could have used more precise terminology but this is hardly the only thing they could have been clearer on the wording (JC even being a bit cagey in his response, but there is a character limit on twitter). You have to be within 60' of the caster, but seeing the illusion itself seems to be enough as long as your within that range. That's pretty convoluted, IMO.


As he mentions that the counterspeller has to be within 60' of the cleric, not the illusion, I think this seems consistent with the above. That the cleric, and not the illusion, is the source of the magic - even if the point of origin is the illusion.