For sure. War Caster is the special sauce we want on every recipe
That feels like moving the goalposts, but perhaps in a way that doesn’t really matter all that much

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The Bonus Action muddies the water… yes, the Bard could use it and attain the same number of attacks as the Fighter with Nick who isn’t using their BA… but then we could say "if the Fighter took DW, then they could also use their BA and have one more attack again". It would also be true, but it’s an escalation of resources, and not an apples-to-apples comparison. We went from comparing number of attacks per AA across two builds to comparing number of attacks per AA for build 1 vs per AA+BA for build 2, and then jumped to number of attacks per BA+AA for build 3 (which BTW also costs one more feat). It’s fine to lay out all our cards on the table and mention all the options, but at some point we also have to lock down the parameters otherwise we’re continuously expanding the scope of what each build spends to outdo the other

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Anyhow…
I will certainly shake hands on the Bard being subpar. That, in a sense, is probably how it should be. (Take that, Bard lovers

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I’m not convinced about the Bladesinger though… a Fighter 2 (or more!) / Bladesinger X build seems quite reasonable to me…