D&D 5E Can you twin booming blade

[Paul Farquhar]

obviously

= making sh*t up.

 

[Esker]

Or that instead of one ray, there are two rays. DMs should make up their own mind about this kind of thing, but some admirble DMs will stop that kind of exploit cold.

Others will stop that kind of cold exploit...

 

[lumenbeing]

Actually, that's exactly what it does. The caster has taken the Cast a Spell action, so normally they would not be able to make a melee attack at all; the spell provides an exception. There's no particular reason to say that Twinning doesn't extend that exception.

There is a particular reason and I've said it before. Here it is again. If the requirement (implicit in the word "must") was a price in gold rather than "make an attack with a melee weapon" no one would be arguing that twinning the spell puts the needed gold in the casters pocket.

Yes the spell creates an exception, but not in that it grants a melee attack, but rather in that it imposes an additional requirement (like a component) as a threshold limit on the spell. You aren't "able to" make an attack with a melee weapon, you HAVE TO. You "must". Otherwise the spell fails. And as you say, there is "no particular reason" to say that Twinning doesn't extend that requirement.

Maybe you have a point about invoking common sense being dubious. I don't agree, but let me state it another way. The degree to which the notion of Twinning Booming blade would necessarily grant an otherwise physically incapable caster of making 2 melee weapon attacks, possibly on opposite sides of him, offends my sense of verisimilitude, and in my reading of the spell description is not at all supported, so rather than inventing ways the twinning of the spell "might" work to further strain my suspension of disbelief, I prefer my argument that Twinning this particular spell is simply not possible unless the caster can fulfill the twinning requirements. And I'm perfectly fine with the characterization of this as a "house rule."

On the other hand, the reason I even bother arguing is this. For whatever reason, arguments are given more weight when they appear on the internet. Some player will surely come along as say, "oooh look, these 5 randoms on EnWorld agree you CAN twin booming blade. And JC tweeted that it grants a second weapon attack. My DM is soooo wrong" So now, officially, not everyone agrees with the "community consensus." You're welcome.

 

[Paul Farquhar]

Yes the spell creates an exception, but not in that it grants a melee attack, but rather in that it imposes an additional requirement (like a component) as a threshold limit on the spell. You aren't "able to" make an attack with a melee weapon, you HAVE TO. You "must".

It says you must make a melee attack, but it does not say you must be able to make a melee attack.

 

[Esker]

It says you must make a melee attack, but it does not say you must be able to make a melee attack.

Right, if you had to be able to make a melee attack, then the spell would never work, since you've already used your action to cast a spell. I guess maybe if you had a Scimitar of Speed? Actually no, not even then, since it says the attack has to be part of the same action!

 

[Esker]

On the other hand, the reason I even bother arguing is this. For whatever reason, arguments are given more weight when they appear on the internet. Some player will surely come along as say, "oooh look, these 5 randoms on EnWorld agree you CAN twin booming blade. And JC tweeted that it grants a second weapon attack. My DM is soooo wrong" So now, officially, not everyone agrees with the "community consensus." You're welcome.

Dang, somebody has a dissenting opinion that they're posting about this issue on the internet. I guess this is no longer like all those other issues where there's a broad consensus and therefore nobody does that.

 

[lumenbeing]

Hence the reason why we are discussing ray of frost with such passion.

Now if the sorcerer had some special ability -- like, a feat that let them point at two people at once using one hand -- then I could seen permitting this.

Cute.
I'm glad you brought up ray of frost. Its a perfect counterpoint example.

First of all, the text about Twinned Spell on PHB. 102 specifically and clearly says that ray of frost is eligible. No one doubts that and no one has ever made a thread about it, so while imitating my argument is funny, its also not applicable. Now let's look at the differences.

Make a ranged spell Attack against the target

Can you not read the difference between that and this?

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range, otherwise the spell fails.

The ray of frost text doesn't include the words "must make". It just says "Make" Why do you supposed that is? Why does every other spell in every other book (excepting green flame blade which was clearly written by the same person) equally give similar instructions as ray of frost in regards to making a spell attack? No other spells use the words "must make" or make reference to the spell failing. And no other spells mention melee "weapon" attacks. Even shocking grasp, which has also been held up as a comparative example in this thread, says "make a melee spell attack"
A spell attack is a roll of the dice to see if your magic prowess can succeed or not. PHB 205 tells us

Some spells require the caster to make an attack roll to determine whether the spell effect hits the intended target

What Booming Blade does differently is create an additional requirement. A weapon must be used. Not a ghost magic, brought into being by its need to exist weapon which would have been mentioned if that were the intent, just like it is with spiritual weapon. Just "a weapon" that we can assume means one which you are armed with and are capable of wielding. And Its not asking for a "spell attack" of any kind. Magic is not making the attack. The caster is not adding his spell attack mod to the roll. Magic happens if and only if a weapon attack is made in the moment of the casting "otherwise the spell fails"
Success or failure with regards to the attack itself depends on the caster's strength or dex and weapon proficiency, not their magic proficiency. So we can easily conclude that there are no "ghost arms."
If you want double the the damage from the weapon, you have to double the requirement to actually swing that weapon. Physically. And doing so is a lot harder than "pointing at two targets." If it wasn't, then every class would be able to make 2 melee attacks each round.

 

[Esker]

The ray of frost text doesn't include the words "must make". It just says "Make" Why do you supposed that is? Why does every other spell in every other book (excepting green flame blade which was clearly written by the same person) equally give similar instructions as ray of frost in regards to making a spell attack?

My guess is because you actually need to have a weapon in your hand and use it -- you can't use an arcane focus in place of the spell's material component of "a weapon", despite the fact that no GP cost is listed. The spell doesn't provide you with a weapon with which to make the melee weapon attack, it just provides you with the action economy to attack with it.

As I've said before, you can house rule whatever you want, but the only mechanical difference between a character with the extra attack feature and one without is how many attacks they can make when they take the attack action. It's a mechanical distinction. Do you think that when a 4th level fighter goes to bed and wakes up a 5th level fighter, they've suddenly gotten twice as fast at attacking? No; "attacks per round" is an abstraction, included for balance, not realism. When you try to insist that the action economy rules directly govern what is possible for a character in a situation not governed by those rules, you're setting yourself up for all kinds of inconsistencies. The rules are one thing; the flavor is another.

 

[NotAYakk]

Cute.
I'm glad you brought up ray of frost. Its a perfect counterpoint example.

First of all, the text about Twinned Spell on PHB. 102 specifically and clearly says that ray of frost is eligible. No one doubts that and no one has ever made a thread about it, so while imitating my argument is funny, its also not applicable. Now let's look at the differences.

Of course it is usable! It just doesn't great you a second beam. The rules give you an additional target, not a second beam or a second ranged attack roll.

Make a ranged spell Attack against the target

Can you not read the difference between that and this?

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range, otherwise the spell fails.

Yes. One requires that you make a ranged spell attack against a target.
The other requires you make a melee weapon attack against a target.

The ray of frost text doesn't include the words "must make". It just says "Make" Why do you supposed that is?

It constrains which creatures you can make the melee weapon attack, which the spell grants, against.

Why does every other spell in every other book (excepting green flame blade which was clearly written by the same person) equally give similar instructions as ray of frost in regards to making a spell attack?

I've spent some time trying to generate natural wording for "this spell grants a melee weapon attack against its target and on a hit blah", and they all suck.

And no other spells mention melee "weapon" attacks.

Yes, this spell uses the melee weapon attack rules. Not the melee spell attack rules. Melee spell attacks are a rules element described in the combat section that uses your casting modifier. Melee weapon attacks are also described; they use strength, and dexterity sometimes, and charisma on a hexblade warlock.

That is the core of the difference between these spells.

Even shocking grasp, which has also been held up as a comparative example in this thread, says "make a melee spell attack"

Yes, because shocking grasp uses int, cha or wis (depending on which casting stat) to make the attack roll, while this one uses str, dex (if finesse weapon) or (on a hexblade) cha.

A spell attack is a roll of the dice to see if your magic prowess can succeed or not. PHB 205 tells us

Some spells require the caster to make an attack roll to determine whether the spell effect hits the intended target

A spell attack roll is an attack roll you make with your casting stat.

What Booming Blade does differently is create an additional requirement. A weapon must be used. Not a ghost magic, brought into being by its need to exist weapon which would have been mentioned if that were the intent, just like it is with spiritual weapon.

Did I mention a ghost weapon anywhere? No I did not. Why are you bringing up a ghost weapon when responding to me? It also doesn't involve a polymorphed chicken from the moon, nor does it involve upside down pyramids with beholder eyestalks.

Just "a weapon" that we can assume means one which you are armed with and are capable of wielding. And Its not asking for a "spell attack" of any kind.

Attack Rolls
When you make an Attack, your Attack roll determines whether the Attack hits or misses. To make an Attack roll, roll a d20 and add the appropriate modifiers. If the total of the roll plus modifiers equals or exceeds the target’s Armor Class (AC), the Attack hits. The AC of a character is determined at Character Creation, whereas the AC of a monster is in its stat block.

Modifiers to the Roll
When a character makes an Attack roll, the two most Common Modifiers to the Roll are an ability modifier and the character’s Proficiency Bonus. When a monster makes an Attack roll, it uses whatever modifier is provided in its stat block.

Ability Modifier: The ability modifier used for a melee weapon Attack is Strength, and the ability modifier used for a ranged weapon Attack is Dexterity. Weapons that have the Finesse or Thrown property break this rule. Some Spells also require an Attack roll. The ability modifier used for a spell Attack depends on the Spellcasting Ability of the spellcaster.

A spell attack means you use the spellcasting ability of the spellcaster. See above.

Magic is not making the attack.

Magic is causing the attack to happen. Without the spell causing the attack to happen, you are not allowed to cast a spell and make an attack on the same action.

If you say that the spell text doesn't grant you the ability to make an attack while casting it, the spell does nothing. I mean, that is a position. I don't think it is yours. Is it?

So, assuming you agree that booming blade is a spell that does something, then the spell grants you the ability to make an attack while casting it.

[SNIP] more about ghost arms. I am disappointed you aren't also ruling out polymorphed chickens teleporting being caused by the spell. I mean, they aren't caused by the spell either, but you spend so much time talking about ghost arms they might feel left out in also not being mentioned as not happening.

If you want double the the damage from the weapon, you have to double the requirement to actually swing that weapon. Physically. And doing so is a lot harder than "pointing at two targets." If it wasn't, then every class would be able to make 2 melee attacks each round.

Most classes don't have the ability to take the attack action and make two attacks.

Every class can make two attacks each round. Pick up two small rocks (if your DM agrees they are "light": failing that, two daggers). Now make an attack. And make a bonus action attack.

There we go, two attacks in a round.

That is what you said, and it is wrong. Probably because it isn't what you wanted to say; I think you meant "two attacks in an action". To be more clear, it is "two attacks by taking the attack action". And yes, many classes cannot make two attacks by taking the attack action.

No class can make an attack while casting a spell as an action, unless the spell grants an attack. Either booming blade grants an attack, or it doesn't.

Only a few classes can make a spell attack as an action, unless they cast a spell. Some spells grant spell attacks as part of the spell. Either ray of frost grants a spell attack, or it doesn't.

Both booming blade and ray of frost pick a target. Twin spell applies to both, and let you pick an additional target. If both ray or frost and booming blade grant an attack (one a spell attack, one a melee attack), either the ability to attack each target is granted, or not. By the rules as written, no additional attacks are granted by twin spell.

Ray of Frost only deals damage if the Beam hits the target. That beam is described as singular. Booming blade only deals damage if the weapon attack hits the target. That weapon attack is described as singular. Twin Spell does not give two Beams, it just gives another target. So there is no rules text that supports there being a second beam, just as there is no rules text that supports there being a second weapon attack in Booming blade. Without that second swing or beam, the second target cannot be hit, so no effect occurs on them.

Making a ranged spell attack isn't something a sorcerer can do without a spell. Being able to do a ranged spell attack without a spell is very rare -- sun soul monks and the returned dead rogue are the only two that I can think of -- and second ranged spell attack without a spell permitting it is something only radiant sun soul monks can do! Sorcerers simply lack the ability to do it naturally, unless a spell permits them to do it.

And as twin spell doesn't grant a second beam nor a second ranged spell attack, using twin spell on ray of frost is permitted, but mostly useless. Just like Booming Blade.

As a DM, you are free to houserule that ray of frost gets a second beam, but booming blade doesn't. I'm not stopping you. I'm just saying that ray of frost's inability to hit a second target is directly in line with booming blade's inability.

Both grant an attack. One is a melee weapon attack, one is a ranged spell attack. Both have an effect if the attack hits the target. Twin spell works on both, and grants an additional target. Twin spell does not grant an additional attack in either case.

 

[Paul Farquhar]

Right, if you had to be able to make a melee attack, then the spell would never work, since you've already used your action to cast a spell. I guess maybe if you had a Scimitar of Speed? Actually no, not even then, since it says the attack has to be part of the same action!

Which, of course, leads to the conclusion that even if your number of attacks is zero you could still make an attack roll as part of casting the spell.