D&D 5E My Quick and Dirty Tasha Read

[Chaosmancer]

That would be a way to exploit that feature (which would require you to be using Two-Weapon Fighting), but that doesn't invalidate anything I said.

But it shows the fundamental problem with your assertion. You did not take the Attack action, you dodged. Therefore you don't qualify for the Two-Weapon Fighting. What you are proposing is basically disguising other actions as attack actions. Which is not something the game currently allows.

Like I've said a few times before, the RAI is not explicit on this matter. No game designers have stated whether or not they intend for it to work this way.

RAI does not always need the designer telling us what it is. This ability is very explicity in how it works, and when it works.

Moreover is another way of saying "additionally". It doesn't say anything about whether or not you have to make two attacks in order to use this feature. There is a precedent of multiple different abilities being put into the same feature and having "additionally" or "also" to separate those extended benefits.

I hate doing this thing, but quoting Vocabulary.com on "When should you use moreover"

"Breaking moreover into more and over helps you remember what it means: more information over what has already been said. When you hear someone use moreover that tips you off that whatever follows is going to relate to what came before. You can think of moreover as a formal way of saying besides."

"Moreover" and "additionally" are very similiar and used in very similar contexts. But, they have differences. And the big difference with "moreover" is that it is much more explicitly linking what came before and what comes after. While "additionally" can be used to show something that is not as related.

It specifically refers to making an attack, not forcing you to make two attacks in order to use this feature. If you are going to continue arguing that you must make two attacks with this feature in order to gain this benefit (which I know you are, I've been down this road before), I will skip to the end with my next example.

How can you possibly read "one of those attacks" as any attack? It clearly indicates by saying "one of those" as refering to a set of more than one.

If I pointed to a plate and said that you can eat "one of those cookies" and there is only one cookie, you would be slightly confused. Maybe you would think there used to be more, maybe you would think that there are cookies you can't see, but my sentence doesn't make sense if there is only one cookie.

For your reading of this ability, it would have to say "Moreover, you can cast one of your cantrips in place of an attack." That is the phrasing you would need, and that is not what you have.

Imagine a bladesinger using this feature, attacking first with Green-Flame Blade, killing the last two enemies in the battle. There's no one else to attack, and therefore the bladesinger just doesn't attack again. They took the Attack action, because what action you take is determined before the effects of the action happen, but only cast a cantrip.

That scenario would work exactly the same as using Haste to attack once, replacing the attack with a blade cantrip. You aren't forced to make a second attack by the Bladesinger's Extra Attack. That would be ridiculous.

There are a few key differences.

1) You are not required to use all of your attacks when you take the Attack Action and have Extra Attack
2) In your scenario there is nothing that would prevent you from taking the "Cast a Spell" action, so even if that is the only thing you do, that is still a legal move.

And my explanation still holds up, following this. 1)You declare you are taking the Attack Action, 2) you "load up" your extra attack feature. 2b) You then get to determine which of those attacks is a cantrip. 3) Then you roll to hit.

Haste doesn't do this. Haste specifically prevents #2, you cannot use your Extra Attack feature. Since you cannot do #2, you can't do #2b which relies on having activated the feature first. So you jump straight to rolling to hit.

You need to read the rules of Two-Weapon Fighting and stop using strawmen. I never claimed that this would work with a bonus action, because it very clearly wouldn't. The bonus action attack from TWF is not an Attack action. However, the Hasted attack is part of the Attack action.

I know you didn't say that. That is why I know that your reading is wrong, because your reading would allow for the Two-Weapon Fighting attack to be turned into a cantrip. Since we both agree that is wrong, we should be able to agree that turning an attack into a cantrip is only allowed when you are using Extra Attack. Because of the examples I gave with other "actions turned to bonus actions"

Haste lets you take a special attack action that is only a single attack. It cannot reactivate Extra Attack. Since you can't activate your extra attack, you can't change an attack to a cantrip.

. . . I don't know what edition's PHB you're using, but it's definitely not 5e's. Go read the rules on Two-Weapon Fighting and Opportunity Attacks and the Attack action. Neither Two-Weapon Fighting's bonus action nor Opportunity Attacks are the Attack action. They're all different. If the bonus action attack and opportunity attack were the Attack action, then a level 20 fighter would be able to make 4 attacks each Action, Bonus Action, and Opportunity Attack.

That's very explicitly "the Dodge action", so that would work. However, the bonus action attack from TWF is not "the Attack action", so can you please stop pointing to this illegal example as a support for your argument.

You are not listening, but since you seem to want me to keep quoting the PHB, here we go.

Two-Weapon Fighting

"When you take the Attack action and attack with a light melee weapon that you're holding in one hand, you can use a bonus action to attack with a different light melee weapon that you're holding in the other hand."

Attacks of Opportunity

"You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature. The attack occurs right before the creature leaves your reach."

"If there's ever any question whether something you're doing counts as an attack, the rule is simple: if you're making an attack roll, you're making an attack."


So, what does this tell us?

It seems that, perhaps, you might be right that a Bonus Action Attack is not the Attack action. Looking through the monk, they are always very explicit though

"When you use the Attack action with an unarmed strike or a monk weapon on your turn, you can make one unarmed strike as a bonus action."

"Immediately after you take the Attack action on your turn, you can spend 1 ki point to make two unarmed strikes as a bonus action."

Now, this is odd. Why would they need to keep specifying the number of attacks you are allowed with Attacks of Opportunity, Martial Arts, and Flurry of Blows? I mean, if we are meant to read Two-Weapon Fighting as that a Bonus Action attack can not activate Extra attack, why then have all of these other places that specify how many attacks you get, closing the possibility of using Extra Attack?

I mean, according to you, none of these are the Attack Action. They are attacks that don't have a name. There is nothing that is an attack but not an attack action unless you are talking about spell attacks.

So, looking at Attacks of Opportunity and the wording of the monk, since they all specify the number of attacks you get to make, I propose that the intent is generally that attacking is an Attack, whether it is an action or a bonus action, or a reaction. Just like Dodging is the Dodge Action no matter how you use it.

Two-Weapon Fighting then is the outlier, and probably should have the word "single" in the text to indicate this.

Your action doesn't fail, the spell does. You start the casting of Booming Blade/Green-Flame Blade by making a melee weapon attack. Counterspell won't stop your sword from hitting someone, it will just stop the magical effects of the spell.

Your action is the spell. You took the "Cast a Spell" action, the only reason you get to make an attack roll is because of the text of the spell, which is gone. You don't get to benefit from a canceled spell.

And this is already 100% covered in Sage Advice

@JeremyECrawford #Dnd if my Green Flame Blade is Counterspelled, do I still get to make a normal melee attack or is it "counterspelled" too?
— Andrea Back (@VyrelionAB) April 17, 2016

No part of a countered spell occurs. That's the purpose of counterspell. #DnD https://t.co/XPgZvoAHaT
— Jeremy Crawford (@JeremyECrawford) April 17, 2016