Sure, but the attacks are coming from the Attack Action, not from the feature. The feature modifies the attack action. But the attack action always gives at least the one attack.
And, when the feature says "those attacks" it means the attacks you're making with the attack action. Which is what you're doing if you use the fighter's extra attack to modify your attack action anyway.
If you're using the Fighter's Extra Attack feature, you can't "cast one of your cantrips in place of one of those attacks" since this ability comes from the Bladesinger's Extra Attack feature, which is a different feature than the one you're using to modify the Attack action, because the Extra Attack features don't add together. You must use one or the other.
O.K. A twist to this discussion. A Psi-Warrior that has reached a level where it has an extra attack [and has taken the magic initiate feat instead of multi-classing] am i wrong in thinking that a class feature can double a cantrip used as an action with another cantrip as an action. W/out trying to cast a 3rd cantrip, which I think isn't kosher.
O.K. A twist to this discussion. A Psi-Warrior that has reached a level where it has an extra attack [and has taken the magic initiate feat instead of multi-classing] am i wrong in thinking that a class feature can double a cantrip used as an action with another cantrip as an action. W/out trying to cast a 3rd cantrip.
A 5th level Psi Warrior Fighter can cast only 1 spell per Cast a Spell action, so 1 cantrip with his action and possibly another with Action Surge. Extra Attack would have no possible interaction since the Attack action is not used.
edit: i realize now I probably should clarify this is referring to the original bladesinger + fighter topic, not the psi-knight stuff which has been already asnwered
So from what I understand, essentially, stacking doesn't work because mutliclassing rules don't allow Extra Attack to stack, some DMs might argue otherwise because "stack" can be interpreted differently.
If you do allow it:
assuming 65% base hit chance, resourceless (note both have 4 available ASIs which I assume are all going towards stats, this doesn't account for extra damage if BB procs)
If you went another round it'd be avg 62.2 (fighter) vs 58.175 (fighter/bladesinger). Bladesinger will eventually catch up but they already have 2 rounds of BA clog so it'd be probably ~round 7 or so. There is a bit of margin of error cause I didn't account for crits, but I doubt that'll increase the difference between the two more than a couple points (considering both builds can crit).
The Fighter/Wizard/Hexblade might be worse because shadowblade doesn't stack with Hex (both are concentration) and EB is probably worse than BB unless you invest heavily into CHA. Noteworthy that the Fighter/Wizard has 3/4th level spells by this point, they don't need to cast shadowblade I just use it here cause I'm calculating pure dpr. I did not account for EK but then I'd need to account for GWM/PAM going battlemaster which would be a bit annoying.
Overall the bladesinger is probably a bit better cause the additional spells helps a lot (buffs, stuff like False Life, and the above is excluding the chance for BB extra damage to proc but that extra damage is countered by the BA clog), but honestly I'd say it's close enough. You could have both of them on a team and I don't think either would be trampling over the other. Besides, different classes can do similar things (esp. if both of them are built to do the same thing, tank & damage), and not "trample" each other
TDLR; The Fighter is certainly doing more DPR, but the fighter/bladesinger has more utility, control, and a little better burst. Neither tramples the either.
Sure, but the attacks are coming from the Attack Action, not from the feature. The feature modifies the attack action. But the attack action always gives at least the one attack.
And, when the feature says "those attacks" it means the attacks you're making with the attack action. Which is what you're doing if you use the fighter's extra attack to modify your attack action anyway.
If you're using the Fighter's Extra Attack feature, you can't "cast one of your cantrips in place of one of those attacks" since this ability comes from the Bladesinger's Extra Attack feature, which is a different feature than the one you're using to modify the Attack action, because the Extra Attack features don't add together. You must use one or the other.
O.K. A twist to this discussion. A Psi-Warrior that has reached a level where it has an extra attack [and has taken the magic initiate feat instead of multi-classing] am i wrong in thinking that a class feature can double a cantrip used as an action with another cantrip as an action. W/out trying to cast a 3rd cantrip, which I think isn't kosher.
Are you asking if you can cast two (or three) cantrips using the attack action as a class that has extra attack?
The answer is no. Casting a cantrip uses the cast a spell action, it is not part of the attack action and is unaffected by extra attack (bladesinger version notwithstanding)
edit: i realize now I probably should clarify this is referring to the original bladesinger + fighter topic, not the psi-knight stuff which has been already asnwered
So from what I understand, essentially, stacking doesn't work because mutliclassing rules don't allow Extra Attack to stack, some DMs might argue otherwise because "stack" can be interpreted differently.
If you do allow it:
assuming 65% base hit chance, resourceless (note both have 4 available ASIs which I assume are all going towards stats, this doesn't account for extra damage if BB procs)
If you went another round it'd be avg 62.2 (fighter) vs 58.175 (fighter/bladesinger). Bladesinger will eventually catch up but they already have 2 rounds of BA clog so it'd be probably ~round 7 or so. There is a bit of margin of error cause I didn't account for crits, but I doubt that'll increase the difference between the two more than a couple points (considering both builds can crit).
The Fighter/Wizard/Hexblade might be worse because shadowblade doesn't stack with Hex (both are concentration) and EB is probably worse than BB unless you invest heavily into CHA. Noteworthy that the Fighter/Wizard has 3/4th level spells by this point, they don't need to cast shadowblade I just use it here cause I'm calculating pure dpr. I did not account for EK but then I'd need to account for GWM/PAM going battlemaster which would be a bit annoying.
Overall the bladesinger is probably a bit better cause the additional spells helps a lot (buffs, stuff like False Life, and the above is excluding the chance for BB extra damage to proc but that extra damage is countered by the BA clog), but honestly I'd say it's close enough. You could have both of them on a team and I don't think either would be trampling over the other. Besides, different classes can do similar things (esp. if both of them are built to do the same thing, tank & damage), and not "trample" each other
TDLR; The Fighter is certainly doing more DPR, but the fighter/bladesinger has more utility, control, and a little better burst. Neither tramples the either.
It is not really. You cherrypicked your feats and slanted them way from the mullticlass.
You had to pick a fighter with GWM and PAM to slant your comparison towards the single class. However there is nothing preventing the multiclass fighter-bladesinger from wearing Plate and taking GWM/PAM too and using Green Flame Blade with it. There is no minimum dexterity requirement for this multiclass.
Give the bladesinger PAM and GWM and that total goes to 0.4*(3*(1d10+15)+(1d4+15))+0.65*(1d10+3d8+5)=56.9
PLUSanother 3d8+intelligence (0.65*(13.5+1min) to a second opponent for 66.3 total.
Make both of them dual wielding and the damage for both goes down, but the multiclass bladesinger stays on top. Make it dueling and the multiclass bladesinger stays on top. No matter how you slice this if you give them both the same fighting style and the same feats the multiclass bladesinger will always do more damage taking the attack action.
Finally, these numbers don't account for the felxibilty associated with this. You used one of the blade cantrips in your example (as did I) but a bladesinger can cast ANY cantrip as part of the attack action. The multiclass bladesinger can use a save cantrip or a cantrip when the enemy has a high AC, or she can pick a cantrip the enemy has vulnerability to. She can use Lightning Lure to bring him close or use Sapping Sting to drop him prone (and get advantage on the next three attacks if he fails his save). She can use swordburst or thunderclap to do 4d6 to numerous enemies. When she does any of those she only loses 1 attack. The only fighter that can cast a cantrip and make an attack at all is the eldritch knight, but he loses 2 attacks and a bonus action to pull it off, is limited to cantrips with 1-action casting time and he does not have the luxury of changing his cantrips every long rest to match the enemies he thinks he is going to face.
edit: i realize now I probably should clarify this is referring to the original bladesinger + fighter topic, not the psi-knight stuff which has been already asnwered
So from what I understand, essentially, stacking doesn't work because mutliclassing rules don't allow Extra Attack to stack, some DMs might argue otherwise because "stack" can be interpreted differently.
If you do allow it:
assuming 65% base hit chance, resourceless (note both have 4 available ASIs which I assume are all going towards stats, this doesn't account for extra damage if BB procs)
If you went another round it'd be avg 62.2 (fighter) vs 58.175 (fighter/bladesinger). Bladesinger will eventually catch up but they already have 2 rounds of BA clog so it'd be probably ~round 7 or so. There is a bit of margin of error cause I didn't account for crits, but I doubt that'll increase the difference between the two more than a couple points (considering both builds can crit).
The Fighter/Wizard/Hexblade might be worse because shadowblade doesn't stack with Hex (both are concentration) and EB is probably worse than BB unless you invest heavily into CHA. Noteworthy that the Fighter/Wizard has 3/4th level spells by this point, they don't need to cast shadowblade I just use it here cause I'm calculating pure dpr. I did not account for EK but then I'd need to account for GWM/PAM going battlemaster which would be a bit annoying.
Overall the bladesinger is probably a bit better cause the additional spells helps a lot (buffs, stuff like False Life, and the above is excluding the chance for BB extra damage to proc but that extra damage is countered by the BA clog), but honestly I'd say it's close enough. You could have both of them on a team and I don't think either would be trampling over the other. Besides, different classes can do similar things (esp. if both of them are built to do the same thing, tank & damage), and not "trample" each other
TDLR; The Fighter is certainly doing more DPR, but the fighter/bladesinger has more utility, control, and a little better burst. Neither tramples the either.
It is not really. You cherrypicked your feats and slanted them way from the mullticlass.
You had to pick a fighter with GWM and PAM to slant your comparison towards the single class. However there is nothing preventing the multiclass fighter-bladesinger from wearing Plate and taking GWM/PAM too and using Green Flame Blade with it. There is no minimum dexterity requirement for this multiclass.
Give the bladesinger PAM and GWM and that total goes to 0.4*(3*(1d10+15)+(1d4+15))+0.65*(1d10+3d8+5)=56.9
PLUSanother 3d8+intelligence (0.65*(13.5+1min) to a second opponent for 66.3 total.
Make both of them dual wielding and the damage for both goes down, but the multiclass bladesinger stays on top. Make it dueling and the multiclass bladesinger stays on top. No matter how you slice this if you give them both the same fighting style and the same feats the multiclass bladesinger will always do more damage taking the attack action.
Finally, these numbers don't account for the felxibilty associated with this. You used one of the blade cantrips in your example (as did I) but a bladesinger can cast ANY cantrip as part of the attack action. The multiclass bladesinger can use a save cantrip or a cantrip when the enemy has a high AC, or she can pick a cantrip the enemy has vulnerability to. She can use Lightning Lure to bring him close or use Sapping Sting to drop him prone (and get advantage on the next three attacks if he fails his save). She can use swordburst or thunderclap to do 4d6 to numerous enemies. When she does any of those she only loses 1 attack. The only fighter that can cast a cantrip and make an attack at all is the eldritch knight, but he loses 2 attacks and a bonus action to pull it off, is limited to cantrips with 1-action casting time and he does not have the luxury of changing his cantrips every long rest to match the enemies he thinks he is going to face.
Except that you cannot Bladesing while wearing anything better than Light armor, and you cannot make a 2h weapon attack (there goes PAM and GWM). Wearing plate and using a halberd completely negate the core of the Bladesinger subclass, so it is completely irrelevant to the conversation. Yes, you could still use the Extra Attack, but now you are completely squishy and the Extra Attack is now the ONLY feature of the subclass you can use.
That is like trying to figure out how well a monk does while wearing plate and wielding a greatsword. Sure he can now use PAM and GWM, but the rest of his kit is absolutely useless.
Yeah I just kinda used the two most basic "optimized" versions of each build.
Dual-wielding Bladesinger with upcast Shadowblade + Rapier
GWM + PAM Fighter
You could probably optimize both builds better than I did, but that applies just as much to the fighter as it does the bladesinger. I acknowledge that subtle changes that EK Fighter + Bladesinger would allow a higher upcast + War Magic, but countered that the single-fighter battlemaster would boost its damage to match (precision attack + GWM/SS is kinda really busted)
To be honest I wasn't sure what feat to give the Bladesinger (cause I wanted both builds to have the same "extra" ASIs), dual-wielder I admit isn't a great feat, but there wasn't a whole lot else I could give them that would boost their damage.
i did acknowledge the flexibility. In fact i said bladesinger is better than the fighter because of the flexibility (and also because of BB provides battlefield control). My post isn't that bladesinger + fighter isn't strong, it's that the fighter can still stand a chance and won't be "trampled" like everyone seemed to thought.
In order words, bladesinger + fighter is not overpowered, it's just slightly above the optimized power curve. Which makes sense because multiclass two classes like that to make use of a specific synergy and spell does indeed constitute a optimized build in my opinion and should be compared to other equally optimized builds.
also your numbers include 3 glaive attacks, a BA, and then another glaive attack with a cantrip. Your actual damage is
Except that you cannot Bladesing while wearing anything better than Light armor, and you cannot make a 2h weapon attack (there goes PAM and GWM). Wearing plate and using a halberd completely negate the core of the Bladesinger subclass, so it is completely irrelevant to the conversation. Yes, you could still use the Extra Attack, but now you are completely squishy and the Extra Attack is now the ONLY feature of the subclass you can use.
Not if the "core" you are looking for is a multiclass that can do extra attack and use a cantrip and you do not need to be in bladesong to do that.
The bladesong ability itself is what is irrelevant to the conversation.
You are not squishy at all. Remember we are talking about a multiclass and although specifics vary, a FighterX/Bladesinger6 in Plate is going to be LESS squishy than a single class fighter in almost all cases.
With 6 levels of wizard, you have 12 hps less than a single class fighter when you wake up in the morning and upcast false life means you generally enter most fights with a total (regular plus temporary) either about equal or with 5hps MORE than a fighter of the same level. Finally, you also have absorb elements to half elemental damage. Being in plate means you have a good AC (same as the fighter) and much better than a single class fighter when you combine it with shield (or worse PEG).
This stuff combined is WAY better than the 12hps you lost taking wizard levels instead of fighter levels.
Except that you cannot Bladesing while wearing anything better than Light armor, and you cannot make a 2h weapon attack (there goes PAM and GWM). Wearing plate and using a halberd completely negate the core of the Bladesinger subclass, so it is completely irrelevant to the conversation. Yes, you could still use the Extra Attack, but now you are completely squishy and the Extra Attack is now the ONLY feature of the subclass you can use.
Not if the "core" you are looking for is a multiclass that can do extra attack and use a cantrip and you do not need to be in bladesong to do that.
The bladesong ability itself is what is irrelevant to the conversation.
You are not squishy at all. Remember we are talking about a multiclass and although specifics vary, a FighterX/Bladesinger6 in Plate is going to be LESS squishy than a single class fighter in almost all cases.
With 6 levels of wizard, you have 12 hps less than a single class fighter when you wake up in the morning and upcast false life means you generally enter most fights with a total (regular plus temporary) either about equal or with 5hps MORE than a fighter of the same level. Finally, you also have absorb elements to half elemental damage. Being in plate means you have a good AC (same as the fighter) and much better than a single class fighter when you combine it with shield (or worse PEG).
This stuff combined is WAY better than the 12hps you lost taking wizard levels instead of fighter levels.
Sure, but your AC will drop through the floor putting on full plate. Why do that to yourself?
Sure, but your AC will drop through the floor putting on full plate. Why do that to yourself?
It will drop to 18 and 23 with shield spell, that is hardly bad. You would do it because you can dump dexterity to 8 and dump Intelligence to 13 and use heavy two-handed weapons maximizing your damage while also landing cantrip damage, having a good AC, high hps and great defensive reactions.
Plate is going to give you better AC unless you can put at least a 16 in both dexterity and intelligence.
I am not saying that is the best bladesinger, but it probably is the best fighter/bladesinger unless you are going to take at least 10 levels in bladesinger.
Compared to a dex/Intelligence multiclass build, you will do more damage and havemore hps because you can max constitution. If you go hill dwarf S16/D8/C16/I13/W12/CH10 at level 10 (bladesinger 6/Fighter 4) you will have a 20 strength, 92hps (before false life) and AC 23 with shield while still sporting a 10 charisma.
I would not do that on a single-class bladesinger, but on a multiclass fighter-bladesinger? Sure!
Are we calling fighter's plate armor 19 AC "dropping through the floor", in this thread? That's an opinion a person could have, sure.
Anywho, theoretically, a Fight4/Bladesinger7+ would have the Bladesinger's extra attack feature, and spellcasting, in some nice plate AC this character could be pretty interesting. You sneak in PAM and Warcaster (not GWM) and things could get spicy. They'd be slightly less MAD, too, if you focus on the right spells, and don't worry about high int. Vhuman and land a solid: 18/10/16/14/10/10.
And, if you did need higher AC you can still shield + quarterstaff/spear and you'd have 21 AC without any magic items or effects running. 26 AC with shield.
But at this point you're adding 2d8 from the booming blades without even factoring the additional 3d8 if they trigger the rider effect, that and not having a -5 to hit and you'll be doing aight offensively when low effort attacking/cantriping/op spellcasting, so warcaster is better for you here than GWM.
It is a lot like a just-better Eldritch Knight. You'd have 4th level spells at this point instead of a handful of up to 2nd. Bonus if you go Echo Knight for subclass for all sorts of fun shenanigans. Since that ability requires the Attack Action to funnel attacks through it and that is precisely what you are using for your bladesinger's attack/cantrip combo. But Rune Knight, Battlemaster, and even just also Eldritch Knight have solid merits. Probably one of the few builds that a Psi Warrior isn't a mistake, too.
O.K. A twist to this discussion. A Psi-Warrior that has reached a level where it has an extra attack [and has taken the magic initiate feat instead of multi-classing] am i wrong in thinking that a class feature can double a cantrip used as an action with another cantrip as an action. W/out trying to cast a 3rd cantrip, which I think isn't kosher.
A 5th level Psi Warrior Fighter can cast only 1 spell per Cast a Spell action, so 1 cantrip with his action and possibly another with Action Surge. Extra Attack would have no possible interaction since the Attack action is not used.
At last, clarity! I was confusing the terms. Curious, does the fact that the cantrips source is a feat impact anything?
No not really
edit: i realize now I probably should clarify this is referring to the original bladesinger + fighter topic, not the psi-knight stuff which has been already asnwered
So from what I understand, essentially, stacking doesn't work because mutliclassing rules don't allow Extra Attack to stack, some DMs might argue otherwise because "stack" can be interpreted differently.
If you do allow it:
assuming 65% base hit chance, resourceless (note both have 4 available ASIs which I assume are all going towards stats, this doesn't account for extra damage if BB procs)
Level 20 GWM/PAM Fighter: 40% * (4 * (1d10 + 15) + (1d4 + 15)) = 39.8
Level 20 DW Fighter/Wizard: 65% * (4 * (1d8 + 5) + 3d8) = 33.475
Burst damage, action surge for both, 3/4th level shadowblade for wizard:
Level 20 GWM/PAM Fighter: 40% * (8 * (1d10 + 15) + (1d4 + 15)) = 73.4
Round Two: exact same thing 73.4 (avg over two round 73.4)
Level 20 Fighter/Wizard: 65% * (4 * (3d8 + 5) + (2 * 3d8) + 3 * (4.5 + 5)) = 84.175
Round two: 65% * (2 * (3d8 + 5) + (2 * 3d8) + 2 * (4.5 + 5)) = 45.175 (avg over two rounds 64.675)
If you went another round it'd be avg 62.2 (fighter) vs 58.175 (fighter/bladesinger). Bladesinger will eventually catch up but they already have 2 rounds of BA clog so it'd be probably ~round 7 or so. There is a bit of margin of error cause I didn't account for crits, but I doubt that'll increase the difference between the two more than a couple points (considering both builds can crit).
The Fighter/Wizard/Hexblade might be worse because shadowblade doesn't stack with Hex (both are concentration) and EB is probably worse than BB unless you invest heavily into CHA. Noteworthy that the Fighter/Wizard has 3/4th level spells by this point, they don't need to cast shadowblade I just use it here cause I'm calculating pure dpr. I did not account for EK but then I'd need to account for GWM/PAM going battlemaster which would be a bit annoying.
Overall the bladesinger is probably a bit better cause the additional spells helps a lot (buffs, stuff like False Life, and the above is excluding the chance for BB extra damage to proc but that extra damage is countered by the BA clog), but honestly I'd say it's close enough. You could have both of them on a team and I don't think either would be trampling over the other. Besides, different classes can do similar things (esp. if both of them are built to do the same thing, tank & damage), and not "trample" each other
TDLR; The Fighter is certainly doing more DPR, but the fighter/bladesinger has more utility, control, and a little better burst. Neither tramples the either.
if I edit a message, most of the time it's because of grammar. The rest of the time I'll put "Edit:" at the bottom.
Are you asking if you can cast two (or three) cantrips using the attack action as a class that has extra attack?
The answer is no. Casting a cantrip uses the cast a spell action, it is not part of the attack action and is unaffected by extra attack (bladesinger version notwithstanding)
It is not really. You cherrypicked your feats and slanted them way from the mullticlass.
You had to pick a fighter with GWM and PAM to slant your comparison towards the single class. However there is nothing preventing the multiclass fighter-bladesinger from wearing Plate and taking GWM/PAM too and using Green Flame Blade with it. There is no minimum dexterity requirement for this multiclass.
Give the bladesinger PAM and GWM and that total goes to 0.4*(3*(1d10+15)+(1d4+15))+0.65*(1d10+3d8+5)=56.9
PLUS another 3d8+intelligence (0.65*(13.5+1min) to a second opponent for 66.3 total.
Make both of them dual wielding and the damage for both goes down, but the multiclass bladesinger stays on top. Make it dueling and the multiclass bladesinger stays on top. No matter how you slice this if you give them both the same fighting style and the same feats the multiclass bladesinger will always do more damage taking the attack action.
Finally, these numbers don't account for the felxibilty associated with this. You used one of the blade cantrips in your example (as did I) but a bladesinger can cast ANY cantrip as part of the attack action. The multiclass bladesinger can use a save cantrip or a cantrip when the enemy has a high AC, or she can pick a cantrip the enemy has vulnerability to. She can use Lightning Lure to bring him close or use Sapping Sting to drop him prone (and get advantage on the next three attacks if he fails his save). She can use swordburst or thunderclap to do 4d6 to numerous enemies. When she does any of those she only loses 1 attack. The only fighter that can cast a cantrip and make an attack at all is the eldritch knight, but he loses 2 attacks and a bonus action to pull it off, is limited to cantrips with 1-action casting time and he does not have the luxury of changing his cantrips every long rest to match the enemies he thinks he is going to face.
Except that you cannot Bladesing while wearing anything better than Light armor, and you cannot make a 2h weapon attack (there goes PAM and GWM). Wearing plate and using a halberd completely negate the core of the Bladesinger subclass, so it is completely irrelevant to the conversation. Yes, you could still use the Extra Attack, but now you are completely squishy and the Extra Attack is now the ONLY feature of the subclass you can use.
That is like trying to figure out how well a monk does while wearing plate and wielding a greatsword. Sure he can now use PAM and GWM, but the rest of his kit is absolutely useless.
Yeah I just kinda used the two most basic "optimized" versions of each build.
Dual-wielding Bladesinger with upcast Shadowblade + Rapier
GWM + PAM Fighter
You could probably optimize both builds better than I did, but that applies just as much to the fighter as it does the bladesinger. I acknowledge that subtle changes that EK Fighter + Bladesinger would allow a higher upcast + War Magic, but countered that the single-fighter battlemaster would boost its damage to match (precision attack + GWM/SS is kinda really busted)
To be honest I wasn't sure what feat to give the Bladesinger (cause I wanted both builds to have the same "extra" ASIs), dual-wielder I admit isn't a great feat, but there wasn't a whole lot else I could give them that would boost their damage.
i did acknowledge the flexibility. In fact i said bladesinger is better than the fighter because of the flexibility (and also because of BB provides battlefield control). My post isn't that bladesinger + fighter isn't strong, it's that the fighter can still stand a chance and won't be "trampled" like everyone seemed to thought.
In order words, bladesinger + fighter is not overpowered, it's just slightly above the optimized power curve. Which makes sense because multiclass two classes like that to make use of a specific synergy and spell does indeed constitute a optimized build in my opinion and should be compared to other equally optimized builds.
also your numbers include 3 glaive attacks, a BA, and then another glaive attack with a cantrip. Your actual damage is
0.4 * (2 * (1d10 + 15) + (1d4 + 15)) + 0.65 * (1d10 + 5 + 3d8) = 38.96
Fighter was 39.8. That's a little better I guess, but this build also uses another ASI. Oh and the whole not being able to bladesing thing.
if I edit a message, most of the time it's because of grammar. The rest of the time I'll put "Edit:" at the bottom.
Not if the "core" you are looking for is a multiclass that can do extra attack and use a cantrip and you do not need to be in bladesong to do that.
The bladesong ability itself is what is irrelevant to the conversation.
You are not squishy at all. Remember we are talking about a multiclass and although specifics vary, a FighterX/Bladesinger6 in Plate is going to be LESS squishy than a single class fighter in almost all cases.
With 6 levels of wizard, you have 12 hps less than a single class fighter when you wake up in the morning and upcast false life means you generally enter most fights with a total (regular plus temporary) either about equal or with 5hps MORE than a fighter of the same level. Finally, you also have absorb elements to half elemental damage. Being in plate means you have a good AC (same as the fighter) and much better than a single class fighter when you combine it with shield (or worse PEG).
This stuff combined is WAY better than the 12hps you lost taking wizard levels instead of fighter levels.
Sure, but your AC will drop through the floor putting on full plate. Why do that to yourself?
It will drop to 18 and 23 with shield spell, that is hardly bad. You would do it because you can dump dexterity to 8 and dump Intelligence to 13 and use heavy two-handed weapons maximizing your damage while also landing cantrip damage, having a good AC, high hps and great defensive reactions.
Plate is going to give you better AC unless you can put at least a 16 in both dexterity and intelligence.
I am not saying that is the best bladesinger, but it probably is the best fighter/bladesinger unless you are going to take at least 10 levels in bladesinger.
Compared to a dex/Intelligence multiclass build, you will do more damage and havemore hps because you can max constitution. If you go hill dwarf S16/D8/C16/I13/W12/CH10 at level 10 (bladesinger 6/Fighter 4) you will have a 20 strength, 92hps (before false life) and AC 23 with shield while still sporting a 10 charisma.
I would not do that on a single-class bladesinger, but on a multiclass fighter-bladesinger? Sure!
Are we calling fighter's plate armor 19 AC "dropping through the floor", in this thread? That's an opinion a person could have, sure.
Anywho, theoretically, a Fight4/Bladesinger7+ would have the Bladesinger's extra attack feature, and spellcasting, in some nice plate AC this character could be pretty interesting. You sneak in PAM and Warcaster (not GWM) and things could get spicy. They'd be slightly less MAD, too, if you focus on the right spells, and don't worry about high int. Vhuman and land a solid: 18/10/16/14/10/10.
And, if you did need higher AC you can still shield + quarterstaff/spear and you'd have 21 AC without any magic items or effects running. 26 AC with shield.
But at this point you're adding 2d8 from the booming blades without even factoring the additional 3d8 if they trigger the rider effect, that and not having a -5 to hit and you'll be doing aight offensively when low effort attacking/cantriping/op spellcasting, so warcaster is better for you here than GWM.
It is a lot like a just-better Eldritch Knight. You'd have 4th level spells at this point instead of a handful of up to 2nd. Bonus if you go Echo Knight for subclass for all sorts of fun shenanigans. Since that ability requires the Attack Action to funnel attacks through it and that is precisely what you are using for your bladesinger's attack/cantrip combo. But Rune Knight, Battlemaster, and even just also Eldritch Knight have solid merits. Probably one of the few builds that a Psi Warrior isn't a mistake, too.
I got quotes!