Yeah, you're right. I misread it. And I don't see a way around it at level 6 Bladesinger, either. You have to use a physical weapon to use Booming blade, so you can't use Pyschic Blades as your second attack unless you drop it (which is dumb), but technically that's a way, unless I'm overlooking something.
Yea you need to sheathe or drop the weapon you use for BB. Or you could ask your DM for a third arm. ;)
This was where I was wondering how to make this work, the logistics of involving a 3rd weapon. One hand is PBing, the other hand needs to be free for the BA PB... where are you holding a 3rd weapon for BB?
I think you'd need to do this in precisely this order:
Start with no weapons in hand.
Take Attack Action: Attack with 1st PB. It vanishes.
Draw a real weapon with that same hand to use with 2nd attack, sub out for cantrip: BB.
BA: 2nd PB with other, free, hand. it vanishes.
This leaves a drawn weapon in one hand.
But you couldn't easily repeat this every round unless you kept dropping that drawn weapon and drawing a new one.
It is apparently so hard to program Aberrant Mind and Clockwork Soul spell-swapping into dndbeyond they had to remake the game without it rather than implement it.
For me it's a moot point anyway, because I'll never do the draw/drop weapon shenanigans. And also, in my opinion 6 Bladesinger - 3 Soulknife is far less strong than just 9 Bladesinger or 9 Soulknife. This is all just theory crafting.
For the first question, it's pretty clear: When you use the Attack action, you can use the blade. It's probably intended for you to use PB on as many attacks as you get with that action. This would then trigger the requirements for the bonus action attack with the off-hand blade.
It definitely isn't intended to do that.
You can manifest your psionic power as shimmering blades of psychic energy. Whenever you take the Attack action, you can manifest a psychic blade from your free hand and make the attack with that blade. This magic blade is a simple melee weapon with the finesse and thrown properties. It has a normal range of 60 feet and no long range, and on a hit, it deals psychic damage equal to 1d6 plus the ability modifier you used for the attack roll. The blade vanishes immediately after it hits or misses its target, and it leaves no mark on its target if it deals damage.
After you attack with the blade, you can make a melee or ranged weapon attack with a second psychic blade as a bonus action on the same turn, provided your other hand is free to create it. The damage die of this bonus attack is 1d4, instead of 1d6.
You create one (1) PB with the Attack action, which you can use to make one (1) weapon attack before it vanishes. Doing so qualifies you to later create one (1) more PB in your offhand as a Bonus Action (if it was empty when that first attack was made), which you in turn can use to make one (1) weapon attack before it vanishes as part of that same Bonus Action. There's no reading of Soulknife's features that would give one the impression you can create as many PBs as you have attacks to made during the Attack action.
While I agree with you in general, I think the place where it might be murky is that the wording is "whenever you take the Attack action", not "as an Attack action". I've gotten the impression from other rules interpretations that these are often intended to interact with each attack if you happen to also have Extra Attack. I cannot now remember where I think that came up. Regardless of whether we agree on the Extra Attack part, we definitely agree that the bonus action attack is dependent on having attacked with the soul knife during the Attack action.
Without considering Bladesinger, BB/GFB etc require you to attack with a weapon as part of the Cast a Spell action. So the Psychic Blade can't be used in conjunction with BB/GFB.
However Bladesinger 6 allows you to substitute a Cantrip during the Attack action for one of your attacks. This does open up the possibility of attacking with a Psychic Blade as an Attack, then using BB/GFB as a cantrip (but here's where it gets murkier -- does the Blade hang around for you to attack with it, or do you need another weapon ?). Then, since you've attacked with the Psychic Blade using an attack, this triggers your off-hand Psychic blade.
Agree with the Blue: a Bladesinger 6 is the only way to cast Booming Blade with the Attack action rather than the Cast a Spell action. PB triggers to create a PB when taking the Attack action. But you've correctly noted that, because a PB is not a weapon with a cost of 1 sp, you're going to have to use PB on your non-BB weapon attack anyway.
Disagree with the red: nothing is murky about this at all. The PB does not hang around, it vanishes when the attack roll is completed. And even if it did hang around, it is not a suitable component with which to make the BB-attack.
Yes, you're completely correct about the red part. I had forgotten that the text specified that it vanished immediately after a hit or miss. (I should have taken the time to look that part up).
This was where I was wondering how to make this work, the logistics of involving a 3rd weapon. One hand is PBing, the other hand needs to be free for the BA PB... where are you holding a 3rd weapon for BB?
I think you'd need to do this in precisely this order:
But you couldn't easily repeat this every round unless you kept dropping that drawn weapon and drawing a new one.
I'm probably laughing.
It is apparently so hard to program Aberrant Mind and Clockwork Soul spell-swapping into dndbeyond they had to remake the game without it rather than implement it.
For me it's a moot point anyway, because I'll never do the draw/drop weapon shenanigans. And also, in my opinion 6 Bladesinger - 3 Soulknife is far less strong than just 9 Bladesinger or 9 Soulknife. This is all just theory crafting.
While I agree with you in general, I think the place where it might be murky is that the wording is "whenever you take the Attack action", not "as an Attack action". I've gotten the impression from other rules interpretations that these are often intended to interact with each attack if you happen to also have Extra Attack. I cannot now remember where I think that came up. Regardless of whether we agree on the Extra Attack part, we definitely agree that the bonus action attack is dependent on having attacked with the soul knife during the Attack action.
Yes, you're completely correct about the red part. I had forgotten that the text specified that it vanished immediately after a hit or miss. (I should have taken the time to look that part up).