As you may be aware, the new Echo Knight subclass for the fighter released in Explorer's Guide to the Wildemount presents some headaches. As explained by Mr Crawford, the echo is a magical object. This means that many attacks (such as grapple or shove) and spells (such as eldritch blast) cannot target it or affect it whatsoever. I would highly recommend this post by The_Humble_Giant for a broader discussion of the Echo Knight.
As mentioned, many spells cannot target objects. This isn't a new problem as illusions are not creatures and furthermore you have spells like Bigby's hand. However, I couldn't find a resource that listed what spells work on objects, and certainly not on the Echo. So I decided to go through all the spells and make a list of all the spells that can target or affect the echo meaningfully.
I have also included a list of spells which notably don't work at the bottom where I think this lack of effect is unintuitive or significant. I have labelled spells with an asterisk if I am uncertain. Constructive feedback on this is appreciated.
Cantrips
Firebolt
Gust* - depends on echo's weight (I would rule it is the same as the fighter)
Light
Mage hand* - depends on echo's weight
Magic Stone - the stones can be thrown at the echo
Prestigitation - It can be cleaned or soiled haha
Shape water - it can be frozen in ice as its not a creature
Shillelagh
True Strike
1st Level
Catapult* - can definitely be targeted. whether the echo can be used as ammo depends on the echo's weight
Detect magic
Hellish rebuke - The fighter actually does damage, not the echo, so hellish rebuke can then target the fighter provided the caster can see the fighter.
Identify
Magnify gravity - Would seem to work on the echo such that it can't move. But it could just be recreated outside the sphere to nullify the effect.
Thunderous smite - only the extra damage not the save
Thunderwave - depends on whether the echo is an "unsecured object"
Unseen servant - can interact with objects (extent unclear)
Wrathful smite - only the extra damage not the smite effects
Zephyr strike - extra damage and active spell prevents echo opportunity attacks
2nd level
Blur - The fighter actually makes the attack so they would have disadvantage attacking through the echo
Continual flame - you can stick a fire on your echo for some reason
Darkness - is weird, you could cast it on the echo, the echo would then be heavily obscured. Could the fighter fire arrows from the echo at targets the knight can see beyond the darkness (presuming they can't see through the darkness). "any attack you make with that action can originate from your space or the echo's space". I think this tends towards yes they can. It doesn't say the fighter needs to be able to see from the echo's perspective.
Enlarge/reduce - enlarge doesn't change the properties of the echo significantly. Reduce could be useful for moving the echo through narrow tunnels longer than 15 ft to then teleport swap with.
Flame blade - extra damage
Immovable object* - depends on echo's weight
Levitate* - depends on whether the echo is a "loose object". Echo can be resummoned to end the effect on it.
Locate object
Magic mouth
Melf's acid arrow
Nystuls's magic aura
Scorching ray
See invisibility – target can see invisible objects
Silence - immunity to thunder damage would apply to the echo
Wristpocket* - depends on the echo's weight. Pointless since the echo can be dismissed and recreated at will
3rd Level
Daylight
Dispel magic
Flame arrows
Lightning arrow - just the extra damage
Remove curse - echo can just be dispelled
Wind wall* – "Small or smaller flying creatures or objects can't pass through the wall." I read this as "flying objects can't pass through the wall". The echo doesn't have to fly but it can certainly hover. I think this one is at DM's discretion.
4th level
Dimension door – depends on echo’s weight
Otiluke’s resilient sphere* – "not physical objects, energy, or other spell effects—can pass through the barrier, in or out". I am uncertain whether the echo could be summoned on the other side of the sphere.
5th level
Bigby’s hand – clenched fist can target objects
Legend lore
Passwall – echo can be pushed out the way when the passwall is created
Telekinesis - can move an object up to 1000 pounds so probably all echos
Wall of force – however, the echo can be summoned on the other side
Wall of stone – probably opaque so echo can’t be summoned on the other side
6th level
Bones of the earth* – this spell makes no mention of whether you can make the pillar appear under an object rather than a creature. I would rule that you could cast it under the echo.
Chain lightning
Drawmij’s instant summons* – depends on the echo’s weight
Forbiddance – would seem to prevent echo swap teleport
Wall of Ice – acts as a barrier but the echo isn’t affected by the frigid air. If the ice is transparent, the echo could be summoned on the other side
Wall of thorns* – "A creature can move through the wall, albeit slowly and painfully.", no mention of whether objects can. It also explicitly blocks line of sight so the echo can’t be summoned on the other side.
7th level
Crown of stars
Fire storm
Forcecage – the cage is invisible, so the echo can be summoned on the other side of the barrier but the fighter will still need to make the charisma save to teleport out
Mordenkainen’s sword
Prismatic spray* – targeting text is a little unclear whether this only targets creatures
Sequester
Symbol* – could perhaps put the symbol on the echo’s hand and close it, needs more thought
Teleport* – is the echo a “simple object”?
Whirlwind* – is the echo an “unsecured object”?
8th level
Antimagic field – echo temporarily winks out of existence. Fighter should be able to summon a new one outside the field. The field also blocks the fighter from echo swap teleporting out.
Antipathy/Sympathy – echo can be targeted object
9th level
Blade of disaster* – is the echo a “loose object”
Meteor swarm
Storm of vengeance – objects are effected by rounds 2 and 3
Wish – spell can do anything
Notably doesn't work
Alarm - only detects creatures
Disintegrate - doesn’t affect magical objects
Fireball - presuming that echos aren't flammable, which given they are "a hologram with substance", that seems unlikely
Fire shield* – Manifest echo reads: “any attack you make with that action can originate from your space or the echo’s space.” I would argue that the fighter isn’t within 5ft of the caster. The echo isn’t a creature and itself can’t be targeted by the spell.
Mordenkainen’s Faithful Hound – only detects and targets creatures
Prismatic wall – specifies creatures for all effects
Shillelagh - Oh god...now I can't get the image out of my head of a druid/barbarian multiclass snatching up a knight's echo, and transforming him into a stick with which to beat the knight.
Im confused about the intent then. The echo wouldn't gain any benefit from Shillelagh. The echo is not attacking, the knight is, from the echos position. There are other spells that have this same concern, shillelagh is just the most obvious example.
You’re right that it’s kind of a dumb example. What I was trying to say is that a druid with Shillelagh can use its ability (attacking with Wis modifier) to damage the echo. It isn’t negated because of the echo’s abilities. Contrast this to shadow blade for example.
Also, I realised I missed out scorching ray. That can target objects.
As you may be aware, the new Echo Knight subclass for the fighter released in Explorer's Guide to the Wildemount presents some headaches. As explained by Mr Crawford, the echo is a magical object. This means that many attacks (such as grapple or shove) and spells (such as eldritch blast) cannot target it or affect it whatsoever. I would highly recommend this post by The_Humble_Giant for a broader discussion of the Echo Knight.
As mentioned, many spells cannot target objects. This isn't a new problem as illusions are not creatures and furthermore you have spells like Bigby's hand. However, I couldn't find a resource that listed what spells work on objects, and certainly not on the Echo. So I decided to go through all the spells and make a list of all the spells that can target or affect the echo meaningfully.
I have also included a list of spells which notably don't work at the bottom where I think this lack of effect is unintuitive or significant. I have labelled spells with an asterisk if I am uncertain. Constructive feedback on this is appreciated.
Cantrips
Firebolt
Gust* - depends on echo's weight (I would rule it is the same as the fighter)
Light
Mage hand* - depends on echo's weight
Magic Stone - the stones can be thrown at the echo
Prestigitation - It can be cleaned or soiled haha
Shape water - it can be frozen in ice as its not a creature
Shillelagh
True Strike
1st Level
Catapult* - can definitely be targeted. whether the echo can be used as ammo depends on the echo's weight
Detect magic
Hellish rebuke - The fighter actually does damage, not the echo, so hellish rebuke can then target the fighter provided the caster can see the fighter.
Identify
Magnify gravity - Would seem to work on the echo such that it can't move. But it could just be recreated outside the sphere to nullify the effect.
Thunderous smite - only the extra damage not the save
Thunderwave - depends on whether the echo is an "unsecured object"
Unseen servant - can interact with objects (extent unclear)
Wrathful smite - only the extra damage not the smite effects
Zephyr strike - extra damage and active spell prevents echo opportunity attacks
2nd level
Blur - The fighter actually makes the attack so they would have disadvantage attacking through the echo
Continual flame - you can stick a fire on your echo for some reason
Darkness - is weird, you could cast it on the echo, the echo would then be heavily obscured. Could the fighter fire arrows from the echo at targets the knight can see beyond the darkness (presuming they can't see through the darkness). "any attack you make with that action can originate from your space or the echo's space". I think this tends towards yes they can. It doesn't say the fighter needs to be able to see from the echo's perspective.
Enlarge/reduce - enlarge doesn't change the properties of the echo significantly. Reduce could be useful for moving the echo through narrow tunnels longer than 15 ft to then teleport swap with.
Flame blade - extra damage
Immovable object* - depends on echo's weight
Levitate* - depends on whether the echo is a "loose object". Echo can be resummoned to end the effect on it.
Locate object
Magic mouth
Melf's acid arrow
Nystuls's magic aura
See invisibility – target can see invisible objects
Silence - immunity to thunder damage would apply to the echo
Wristpocket* - depends on the echo's weight. Pointless since the echo can be dismissed and recreated at will
3rd Level
Daylight
Dispel magic
Flame arrows
Lightning arrow - just the extra damage
Remove curse - echo can just be dispelled
Wind wall* – "Small or smaller flying creatures or objects can't pass through the wall." I read this as "flying objects can't pass through the wall". The echo doesn't have to fly but it can certainly hover. I think this one is at DM's discretion.
4th level
Dimension door – depends on echo’s weight
Otiluke’s resilient sphere* – "not physical objects, energy, or other spell effects—can pass through the barrier, in or out". I am uncertain whether the echo could be summoned on the other side of the sphere.
5th level
Bigby’s hand – clenched fist can target objects
Legend lore
Passwall – echo can be pushed out the way when the passwall is created
Telekinesis - can move an object up to 1000 pounds so probably all echos
Wall of force – however, the echo can be summoned on the other side
Wall of stone – probably opaque so echo can’t be summoned on the other side
6th level
Bones of the earth* – this spell makes no mention of whether you can make the pillar appear under an object rather than a creature. I would rule that you could cast it under the echo.
Chain lightning
Drawmij’s instant summons* – depends on the echo’s weight
Forbiddance – would seem to prevent echo swap teleport
Wall of Ice – acts as a barrier but the echo isn’t affected by the frigid air. If the ice is transparent, the echo could be summoned on the other side
Wall of thorns* – "A creature can move through the wall, albeit slowly and painfully.", no mention of whether objects can. It also explicitly blocks line of sight so the echo can’t be summoned on the other side.
7th level
Crown of stars
Fire storm
Forcecage – the cage is invisible, so the echo can be summoned on the other side of the barrier but the fighter will still need to make the charisma save to teleport out
Mordenkainen’s sword
Prismatic spray* – targeting text is a little unclear whether this only targets creatures
Sequester
Symbol* – could perhaps put the symbol on the echo’s hand and close it, needs more thought
Teleport* – is the echo a “simple object”?
Whirlwind* – is the echo an “unsecured object”?
8th level
Antimagic field – echo temporarily winks out of existence. Fighter should be able to summon a new one outside the field. The field also blocks the fighter from echo swap teleporting out.
Antipathy/Sympathy – echo can be targeted object
9th level
Blade of disaster* – is the echo a “loose object”
Meteor swarm
Storm of vengeance – objects are effected by rounds 2 and 3
Wish – spell can do anything
Notably doesn't work
Alarm - only detects creatures
Disintegrate - doesn’t affect magical objects
Fireball - presuming that echos aren't flammable, which given they are "a hologram with substance", that seems unlikely
Fire shield* – Manifest echo reads: “any attack you make with that action can originate from your space or the echo’s space.” I would argue that the fighter isn’t within 5ft of the caster. The echo isn’t a creature and itself can’t be targeted by the spell.
Mordenkainen’s Faithful Hound – only detects and targets creatures
Prismatic wall – specifies creatures for all effects
Ravenous void – destroys non-magical objects
Reverse gravity – its RAI that the echo can hover, so this spell probably wouldn’t affect the echo's movement
Shadow blade - Only does psychic damage which the echo is immune to since it's an object (PHB p185)
Shatter - only works on nonmagical objects
Spiritual weapon - can only target creatures
Summon lesser/greater demons* – hostile to all creatures
True polymorph – only targets non-magical objects
Shillelagh - Oh god...now I can't get the image out of my head of a druid/barbarian multiclass snatching up a knight's echo, and transforming him into a stick with which to beat the knight.
Is this a joke lol? "The wood of a club or quarterstaff you are holding is imbued with nature's power. ..."
Im confused about the intent then. The echo wouldn't gain any benefit from Shillelagh. The echo is not attacking, the knight is, from the echos position. There are other spells that have this same concern, shillelagh is just the most obvious example.
You’re right that it’s kind of a dumb example. What I was trying to say is that a druid with Shillelagh can use its ability (attacking with Wis modifier) to damage the echo. It isn’t negated because of the echo’s abilities. Contrast this to shadow blade for example.
Also, I realised I missed out scorching ray. That can target objects.
Super helpful thanks!