I'm considering a druid with the War Caster feat. I'm having some troubles finding which spells would be castable using the following benefit of said feat:
When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.
So, Blight and Polymorph are the lowest level Druid spells of which I am sure they can be used with this feat.
I am pretty sure that using Ice Knife is allowed but it is not that interesting because if I use it as an opportunity attack I will have to eat the splash damage myself.
Hold Person might also be allowed but only if you do not use a higher level spell slot.
Would Thunderwave be allowed if there is only on target in the AoE?
I doubt Heat Metal is allowed as it targets metal objects and not creatures.
Don't forget cantrips, but druid cantrips are a little weird. Maybe Poison Spray? Gust might be situationally useful. Infestation and Thorn Whip could be useful. Just keep in mind that some of those might be ranged spell attacks and subject to disadvantage when someone is within 5 feet of you.
Edits: First two spells didn't qualify, so I finally looked up the druid spell list.
The description doesn't say that it can target only one creature, just that it must target only one creature. So the spell can target more creatures as long as this casting targets only one.
That may be an unpopular view but I think it's the only consistent way to read it considering the language for sorcerer twin spell metamagic.
Generally, the rules for AOE spells target a point in space and not a creature, so they're out. Thunderwave is out, no matter how many people are in the area because the target is self. There was quite a lengthy discussion about what a target of a spell is, since the rules use "target" to sometimes mean "point of aim" and sometimes to mean "affected creature" within spell descriptions and rules, so there is some confusion about ice knife. I tend to be on the side of limiting it, since even though the point of aim is one creature, every other spell that affects more than one creature is off limits (-this is a balance, not RAW argument). Anyway, as you pointed out, if you do use ice knife as an AoO attack when you yourself aren't using a reach weapon, you'd be in the AoE too.
Leveled spells between 1 and 3 are quite limited for druid in that way: most of the damage spells are area of effect (like erupting earth) or area of effect and concentration (like moonbeam). Some circles may give you access to spells that may work (such as acid arrow). And as Jhfffan pointed out, cantrips are a good possibility, though without the new UA, Acid Splash isn't a druid cantrip. Just about every druid attack cantrip targets only one creature except thunderclap and the attack enhancement ones.
The description doesn't say that it can target only one creature, just that it must target only one creature. So the spell can target more creatures as long as this casting targets only one.
That may be an unpopular view but I think it's the only consistent way to read it considering the language for sorcerer twin spell metamagic.
The language of that metamagic was eratta’ed because it used similar language to what is used here. I feel that not making both match was an oversight rather than an intentional choice. The sorcerer metamagic has words added that explains what targeting one creature means, not words that change the meanings of the previous sentences.
Generally, the rules for AOE spells target a point in space and not a creature, so they're out. Thunderwave is out, no matter how many people are in the area because the target is self. There was quite a lengthy discussion about what a target of a spell is, since the rules use "target" to sometimes mean "point of aim" and sometimes to mean "affected creature" within spell descriptions and rules, so there is some confusion about ice knife. I tend to be on the side of limiting it, since even though the point of aim is one creature, every other spell that affects more than one creature is off limits (-this is a balance, not RAW argument). Anyway, as you pointed out, if you do use ice knife as an AoO attack when you yourself aren't using a reach weapon, you'd be in the AoE too.
Leveled spells between 1 and 3 are quite limited for druid in that way: most of the damage spells are area of effect (like erupting earth) or area of effect and concentration (like moonbeam). Some circles may give you access to spells that may work (such as acid arrow). And as Jhfffan pointed out, cantrips are a good possibility, though without the new UA, Acid Splash isn't a druid cantrip. Just about every druid attack cantrip targets only one creature except thunderclap and the attack enhancement ones.
Yeah, I was thinking of Poison Spray and couldn't come up with that name without looking at the spell list. Frostbite would be a good option, particularly if you had PAM to trigger the AoO as they came into range.
I'm considering a druid with the War Caster feat. I'm having some troubles finding which spells would be castable using the following benefit of said feat:
When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.
So, Blight and Polymorph are the lowest level Druid spells of which I am sure they can be used with this feat.
I am pretty sure that using Ice Knife (1) is allowed but it is not that interesting because if I use it as an opportunity attack I will have to eat the splash damage myself.
Hold Person (2) might also be allowed but only if you do not use a higher level spell slot.
Would Thunderwave (3) be allowed if there is only on target in the AoE?
I doubt Heat Metal (4) is allowed as it targets metal objects and not creatures.
Where do you draw the line?
Thanks, Tom
Ice Knife is not allowed. It can target more than one creature.
Hold Person is allowed only when being cast using a 2nd level spell slot. It cannot be upcast to a higher level spell, and it can't be cast with a higher spell slot as a 2nd level spell. Personally, I believe this interaction should preclude it from being eligible at all. Needing to break things down to the point of which spell slots can be used--casting the same spell--for determining interaction with other features is a level of pedantry for which I can't fathom the appeal. Jeremy Crawford disagrees.
Thunderwave is not allowed. It can target more than one creature.
Heat Metal is not allowed. Even though the effect of the spell applies to a creature, it does not target a creature. The attack of opportunity is provoked by a creature, not what they're wearing. The spell is intended to function in this way, and War Caster reaffirms that it only functions with spells that are single-target ("that creature").
The line is very clear: If the spell targets a singular creature (the one which provoked the AoO), is incapable of affecting any other creatures (whether they are present or not), and has a casting time of 1 action, it is eligible for use with War Caster.
Rollback Post to RevisionRollBack
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
The language of that metamagic was eratta’ed because it used similar language to what is used here. I feel that not making both match was an oversight rather than an intentional choice. The sorcerer metamagic has words added that explains what targeting one creature means, not words that change the meanings of the previous sentences.
That's not my interpretation.
Twinned Spell
When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).
To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.
Nothing in there modifies the meaning of targeting.
JC tweeted that, "Dragon's breath can affect more than one creature with the exhalation. It therefore can't be twinned."
To me this means that affecting and targeting are the same with respect to spells. Admittedly, this is the weakest point of my argument.
Twinned spell has the extra language that the spell must be incapable of targeting more than one creature that warcaster does not. To say that not including this extra language in warcaster is a big step away from RAW to speculative RAI.
Whatever the ruling of the DM, it should be consistent for both metamagic and warcaster.
The line is very clear: If the spell targets a singular creature (the one which provoked the AoO), is incapable of affecting any other creatures (whether they are present or not), and has a casting time of 1 action, it is eligible for use with War Caster.
War Caster doesn't work like Twinned spell. Twinned Spell works as you describe; the spell can't even have the possibility of additional targets. War Caster places the restriction on how the spell is used; you must target only that one creature. That still rules out area spells, but still permits spells that have the potential of affecting multiple chosen targets if you don't choose any additional targets. E.g. hold person can still be used at a higher level as long as you forego additional targets, and eldritch blast works if you aim all the beams at the same creature.
I'm considering a druid with the War Caster feat. I'm having some troubles finding which spells would be castable using the following benefit of said feat:
When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.
So, Blight and Polymorph are the lowest level Druid spells of which I am sure they can be used with this feat.
I am pretty sure that using Ice Knife (1) is allowed but it is not that interesting because if I use it as an opportunity attack I will have to eat the splash damage myself.
Hold Person (2) might also be allowed but only if you do not use a higher level spell slot.
Would Thunderwave (3) be allowed if there is only on target in the AoE?
I doubt Heat Metal (4) is allowed as it targets metal objects and not creatures.
Where do you draw the line?
Thanks, Tom
Ice Knife is not allowed. It can target more than one creature.
Hold Person is allowed only when being cast using a 2nd level spell slot. It cannot be upcast to a higher level spell, and it can't be cast with a higher spell slot as a 2nd level spell. Personally, I believe this interaction should preclude it from being eligible at all. Needing to break things down to the point of which spell slots can be used--casting the same spell--for determining interaction with other features is a level of pedantry for which I can't fathom the appeal. Jeremy Crawford disagrees.
Thunderwave is not allowed. It can target more than one creature.
Heat Metal is not allowed. Even though the effect of the spell applies to a creature, it does not target a creature. The attack of opportunity is provoked by a creature, not what they're wearing. The spell is intended to function in this way, and War Caster reaffirms that it only functions with spells that are single-target ("that creature").
The line is very clear: If the spell targets a singular creature (the one which provoked the AoO), is incapable of affecting any other creatures (whether they are present or not), and has a casting time of 1 action, it is eligible for use with War Caster.
Just a comment, but as far as I can tell you can use hold person with higher level spell slots with war caster if you like. The only requirement is that you only target one creature with the spell. Hold person allows you to target more at higher levels but you don't have to and War Caster doesn't have the same wording as the sorcerer twin meta magic in terms of spell selection.
Yeah, I was thinking of Poison Spray and couldn't come up with that name without looking at the spell list. Frostbite would be a good option, particularly if you had PAM to trigger the AoO as they came into range.
I was indeed thinking of getting PAM along the way but I somehow completely overlooked Frostbite as a candidate. Thanks for the hint, I think I will take Frostbite instead of Magic Stone then.
The language of that metamagic was eratta’ed because it used similar language to what is used here. I feel that not making both match was an oversight rather than an intentional choice. The sorcerer metamagic has words added that explains what targeting one creature means, not words that change the meanings of the previous sentences.
That's not my interpretation.
Twinned Spell
When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).
To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.
Nothing in there modifies the meaning of targeting.
JC tweeted that, "Dragon's breath can affect more than one creature with the exhalation. It therefore can't be twinned."
To me this means that affecting and targeting are the same with respect to spells. Admittedly, this is the weakest point of my argument.
Twinned spell has the extra language that the spell must be incapable of targeting more than one creature that warcaster does not. To say that not including this extra language in warcaster is a big step away from RAW to speculative RAI.
Whatever the ruling of the DM, it should be consistent for both metamagic and warcaster.
To be fair, I did say that it was opinion. Also, I think you mean that the rulings for metamagic and warcaster should be inconsistent, because your argument seems to reflect that. I also said exactly that the sentences added don't change the previous sentences, they just explain what "targets only one creature" means: "must be incapable of targeting more than one creature..."
My thought is "must only target that creature" should be read the same way as "must only target one creature that is the creature triggering the AoO," and that a restriction on spells to targeting only one creature (whether it is any one creature or one particular creature that has triggered an AoO) is the same for metamagic and warcaster. And, as I said, since Warcaster was not edited in errata like metamagic, that IS only an opinion. My opinion is that errata only clarified what a spell with only one target is - before the errata, a reasonable reading of the Twinned Metamagic would have given the same list of spells as after. I am of the opinion that the metamagic was only changed to hedge out people who were trying to use an unreasonable reading to cast a couple of fireballs or whatever.
The line is very clear: If the spell targets a singular creature (the one which provoked the AoO), is incapable of affecting any other creatures (whether they are present or not), and has a casting time of 1 action, it is eligible for use with War Caster.
War Caster doesn't work like Twinned spell. Twinned Spell works as you describe; the spell can't even have the possibility of additional targets. War Caster places the restriction on how the spell is used; you must target only that one creature. That still rules out area spells, but still permits spells that have the potential of affecting multiple chosen targets if you don't choose any additional targets. E.g. hold person can still be used at a higher level as long as you forego additional targets, and eldritch blast works if you aim all the beams at the same creature.
I disagree, and I'm with Wolf on this one; I believe the lack of exact language is an oversight, not intentional. If they truly meant for there to be such a distinction, it causes more problems than it solves. In such a scenario, a Warlock/Sorcerer with War Caster (via Variant Human or ASI) would be able to use Eldritch Blast as an AoO with impunity (so long as it's only 1 target), but they would only be able to use it with Twinned Spell from character levels 1-4. As soon as they hit level 5, they are suddenly unable to ever twin it again. That doesn't pass a design sniff-test to me; EB should not be eligible for either at any point in a character's career.
It also opens up a potential can of worms on things that have been argued to death like Green-Flame Blade. It's been my understanding that this spell was a definitive "no" when it comes to both WC & TS, but if nobody else actually takes the splash damage it's suddenly viable for use with WC? If you can simply choose to not target more than one creature, as Mearls asserts is the case, then can I cast a Fireball that only applies to one creature? An Ice Knife with no explosion? I don't believe that's the case. You can't be targeted by a spell if you're in full cover, but you can cast from full cover without issue. Can a point-blank Ice Knife be cast with War Caster if you are ineligible to be targeted by the AoE in return? Yet none of these things work with Twinned Spell because it was errata'd for being prominently in the public eye? I don't buy it.
I don't believe that's the correct intended interaction for WC, nor do I believe that TS is meant to have variable restrictions on the same spell. TS was only errata'd because the question comes up so frequently, and I believe not updating War Caster to match is a mistake. Crawford and Mearls don't even seem to agree with each other on how TS is supposed to work, so I do not trust they have a consensus on how WC is supposed to actually work, or that it is functionally any different from TS. RAI, the targeting restrictions on War Caster are the same as Twinned Spell (errata).
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
To be fair, I did say that it was opinion. Also, I think you mean that the rulings for metamagic and warcaster should be inconsistent, because your argument seems to reflect that. I also said exactly that the sentences added don't change the previous sentences, they just explain what "targets only one creature" means: "must be incapable of targeting more than one creature..."
My thought is "must only target that creature" should be read the same way as "must only target one creature that is the creature triggering the AoO," and that a restriction on spells to targeting only one creature (whether it is any one creature or one particular creature that has triggered an AoO) is the same for metamagic and warcaster. And, as I said, since Warcaster was not edited in errata like metamagic, that IS only an opinion. My opinion is that errata only clarified what a spell with only one target is - before the errata, a reasonable reading of the Twinned Metamagic would have given the same list of spells as after. I am of the opinion that the metamagic was only changed to hedge out people who were trying to use an unreasonable reading to cast a couple of fireballs or whatever.
Consistent doesn't mean the same. It means that the logic should add up. One says that the spell can only target one creature the other says that the spell does target only one creature. It is consistent to say that magic missile is not usable by twinned spell, but is usable with warcaster (provided that the spell only targets one creature), if my premises are to be believed. It is inconsistent if your premises are to be believed. Maybe consistent wasn't the word I was looking for.
"To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level." doesn't change the previous sentences, but it does further limit which spells qualify for twinned spell metamagic. Because it further limits the spells, I have to disagree that it is merely an explanation. Or maybe rather, if it is an explanation here I think it's a big logical leap to generalize explanation here to every use of similar, but not identical, language.
I understand that you're expressing an opinion about RAI, and if you're the DM those are the decisions you get to make, but I think I would be somewhat frustrated if I were a player at your table.
Consistency would have been to errata both since both describe spells that only target one creature, but people seem to not be able to interpret what that means and need clarification.
Edit: to be clear, my entire point is that the pre errata language is so similar that there is no reasonable way to read the two features differently: they require single target spells. The addition of the errata doesn't change the reading of the original sentences, it only gives a definition of what a single target spell is. It is a problem that both features don't give the same definition, since they both apparently rely on it.
Consistency would have been to errata both since both describe spells that only target one creature, but people seem to not be able to interpret what that means and need clarification.
Edit: to be clear, my entire point is that the pre errata language is so similar that there is no reasonable way to read the two features differently: they require single target spells. The addition of the errata doesn't change the reading of the original sentences, it only gives a definition of what a single target spell is. It is a problem that both features don't give the same definition, since they both apparently rely on it.
Thank you for explaining, again. Sometime it can take a bit to sink in. Now that I understand better what your position is, I looked at the issue again as if it was pre-errata. You are right that before the errata they are very similar. I still think you're wrong when you say, "there is no reasonable way to read the two features differently." Let me try to explain.
Twinned Spell: "When you cast a spell that targets only one creature and doesn’t have a range of self..."
Warcaster: "...The spell must have a casting time of 1 action and must target only that creature."
A spell that "targets only one creature" is a statement about the spell's capability. This language is a little loose, so I think it could be interpreted differently. I can see why WotC felt the need to add the errata.
A spell that "must target only that creature" cannot be read as a statement about the spell's capability unless in the text of the spell it calls out "that" specific creature. Since no spell targets "that" specific creature, e.g. no spell that targets "unnamed bugbear 3 in the cave north of Red Larch," it must be a statement about that instance of a casting of the spell.
Hi,
I'm considering a druid with the War Caster feat. I'm having some troubles finding which spells would be castable using the following benefit of said feat:
Where do you draw the line?
Thanks,
Tom
Don't forget cantrips, but druid cantrips are a little weird. Maybe Poison Spray? Gust might be situationally useful. Infestation and Thorn Whip could be useful. Just keep in mind that some of those might be ranged spell attacks and subject to disadvantage when someone is within 5 feet of you.
Edits: First two spells didn't qualify, so I finally looked up the druid spell list.
The description doesn't say that it can target only one creature, just that it must target only one creature. So the spell can target more creatures as long as this casting targets only one.
That may be an unpopular view but I think it's the only consistent way to read it considering the language for sorcerer twin spell metamagic.
Generally, the rules for AOE spells target a point in space and not a creature, so they're out. Thunderwave is out, no matter how many people are in the area because the target is self. There was quite a lengthy discussion about what a target of a spell is, since the rules use "target" to sometimes mean "point of aim" and sometimes to mean "affected creature" within spell descriptions and rules, so there is some confusion about ice knife. I tend to be on the side of limiting it, since even though the point of aim is one creature, every other spell that affects more than one creature is off limits (-this is a balance, not RAW argument). Anyway, as you pointed out, if you do use ice knife as an AoO attack when you yourself aren't using a reach weapon, you'd be in the AoE too.
Leveled spells between 1 and 3 are quite limited for druid in that way: most of the damage spells are area of effect (like erupting earth) or area of effect and concentration (like moonbeam). Some circles may give you access to spells that may work (such as acid arrow). And as Jhfffan pointed out, cantrips are a good possibility, though without the new UA, Acid Splash isn't a druid cantrip. Just about every druid attack cantrip targets only one creature except thunderclap and the attack enhancement ones.
The language of that metamagic was eratta’ed because it used similar language to what is used here. I feel that not making both match was an oversight rather than an intentional choice. The sorcerer metamagic has words added that explains what targeting one creature means, not words that change the meanings of the previous sentences.
Yeah, I was thinking of Poison Spray and couldn't come up with that name without looking at the spell list. Frostbite would be a good option, particularly if you had PAM to trigger the AoO as they came into range.
The line is very clear: If the spell targets a singular creature (the one which provoked the AoO), is incapable of affecting any other creatures (whether they are present or not), and has a casting time of 1 action, it is eligible for use with War Caster.
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
That's not my interpretation.
Nothing in there modifies the meaning of targeting.
Whatever the ruling of the DM, it should be consistent for both metamagic and warcaster.
War Caster doesn't work like Twinned spell. Twinned Spell works as you describe; the spell can't even have the possibility of additional targets. War Caster places the restriction on how the spell is used; you must target only that one creature. That still rules out area spells, but still permits spells that have the potential of affecting multiple chosen targets if you don't choose any additional targets. E.g. hold person can still be used at a higher level as long as you forego additional targets, and eldritch blast works if you aim all the beams at the same creature.
The Forum Infestation (TM)
Just a comment, but as far as I can tell you can use hold person with higher level spell slots with war caster if you like. The only requirement is that you only target one creature with the spell. Hold person allows you to target more at higher levels but you don't have to and War Caster doesn't have the same wording as the sorcerer twin meta magic in terms of spell selection.
Thanks for all the replies all, I think I have a clearer view of it now though it does not seem to be set in stone.
How do you create the links to the spell descriptions BTW?
https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/9811-how-to-add-tooltips
Mega Yahtzee Thread:
Highest 41: brocker2001 (#11,285).
Yahtzee of 2's: Emmber (#36,161).
Lowest 9: JoeltheWalrus (#312), Emmber (#12,505) and Dertinus (#20,953).
I was indeed thinking of getting PAM along the way but I somehow completely overlooked Frostbite as a candidate. Thanks for the hint, I think I will take Frostbite instead of Magic Stone then.
Primal savagery is also a good option if you have it.
I thought of that but it targets self.
To be fair, I did say that it was opinion. Also, I think you mean that the rulings for metamagic and warcaster should be inconsistent, because your argument seems to reflect that. I also said exactly that the sentences added don't change the previous sentences, they just explain what "targets only one creature" means: "must be incapable of targeting more than one creature..."
My thought is "must only target that creature" should be read the same way as "must only target one creature that is the creature triggering the AoO," and that a restriction on spells to targeting only one creature (whether it is any one creature or one particular creature that has triggered an AoO) is the same for metamagic and warcaster. And, as I said, since Warcaster was not edited in errata like metamagic, that IS only an opinion. My opinion is that errata only clarified what a spell with only one target is - before the errata, a reasonable reading of the Twinned Metamagic would have given the same list of spells as after. I am of the opinion that the metamagic was only changed to hedge out people who were trying to use an unreasonable reading to cast a couple of fireballs or whatever.
I disagree, and I'm with Wolf on this one; I believe the lack of exact language is an oversight, not intentional. If they truly meant for there to be such a distinction, it causes more problems than it solves. In such a scenario, a Warlock/Sorcerer with War Caster (via Variant Human or ASI) would be able to use Eldritch Blast as an AoO with impunity (so long as it's only 1 target), but they would only be able to use it with Twinned Spell from character levels 1-4. As soon as they hit level 5, they are suddenly unable to ever twin it again. That doesn't pass a design sniff-test to me; EB should not be eligible for either at any point in a character's career.
It also opens up a potential can of worms on things that have been argued to death like Green-Flame Blade. It's been my understanding that this spell was a definitive "no" when it comes to both WC & TS, but if nobody else actually takes the splash damage it's suddenly viable for use with WC? If you can simply choose to not target more than one creature, as Mearls asserts is the case, then can I cast a Fireball that only applies to one creature? An Ice Knife with no explosion? I don't believe that's the case. You can't be targeted by a spell if you're in full cover, but you can cast from full cover without issue. Can a point-blank Ice Knife be cast with War Caster if you are ineligible to be targeted by the AoE in return? Yet none of these things work with Twinned Spell because it was errata'd for being prominently in the public eye? I don't buy it.
I don't believe that's the correct intended interaction for WC, nor do I believe that TS is meant to have variable restrictions on the same spell. TS was only errata'd because the question comes up so frequently, and I believe not updating War Caster to match is a mistake. Crawford and Mearls don't even seem to agree with each other on how TS is supposed to work, so I do not trust they have a consensus on how WC is supposed to actually work, or that it is functionally any different from TS. RAI, the targeting restrictions on War Caster are the same as Twinned Spell (errata).
You don't know what fear is until you've witnessed a drunk bird divebombing you while carrying a screaming Kobold throwing fire anywhere and everywhere.
Consistent doesn't mean the same. It means that the logic should add up. One says that the spell can only target one creature the other says that the spell does target only one creature. It is consistent to say that magic missile is not usable by twinned spell, but is usable with warcaster (provided that the spell only targets one creature), if my premises are to be believed. It is inconsistent if your premises are to be believed. Maybe consistent wasn't the word I was looking for.
"To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level." doesn't change the previous sentences, but it does further limit which spells qualify for twinned spell metamagic. Because it further limits the spells, I have to disagree that it is merely an explanation. Or maybe rather, if it is an explanation here I think it's a big logical leap to generalize explanation here to every use of similar, but not identical, language.
I understand that you're expressing an opinion about RAI, and if you're the DM those are the decisions you get to make, but I think I would be somewhat frustrated if I were a player at your table.
Consistency would have been to errata both since both describe spells that only target one creature, but people seem to not be able to interpret what that means and need clarification.
Edit: to be clear, my entire point is that the pre errata language is so similar that there is no reasonable way to read the two features differently: they require single target spells. The addition of the errata doesn't change the reading of the original sentences, it only gives a definition of what a single target spell is. It is a problem that both features don't give the same definition, since they both apparently rely on it.
Thank you for explaining, again. Sometime it can take a bit to sink in. Now that I understand better what your position is, I looked at the issue again as if it was pre-errata. You are right that before the errata they are very similar. I still think you're wrong when you say, "there is no reasonable way to read the two features differently." Let me try to explain.
A spell that "targets only one creature" is a statement about the spell's capability. This language is a little loose, so I think it could be interpreted differently. I can see why WotC felt the need to add the errata.
A spell that "must target only that creature" cannot be read as a statement about the spell's capability unless in the text of the spell it calls out "that" specific creature. Since no spell targets "that" specific creature, e.g. no spell that targets "unnamed bugbear 3 in the cave north of Red Larch," it must be a statement about that instance of a casting of the spell.