As Vylix points out, Booming Blade deals an addition 2d8 damage if the target moves before the start of your next turn. This damage is not affected by the critical hit.
Can you crit with booming blade?
What triggers booming blade? The Boom effect is triggered by movement that occurs AFTER the attack hits. Ergo they are not simultaneous. Ergo the Boom effect cannot crit.
Do you double poison damage on a crit?
There is only the rule specifically on critical hits which says any other damage dice involved in the attack are doubled. The poison damage dice of Giant Poisonous Snake is incontrovertibly involved in the attack roll of the Bite action.
Can Spell attacks crit?
It does not specify weapon attacks. If the spell requires an attack roll, it can crit. Considering other spells always hit bit might only deal half, and attack spells might miss completely, I think allowing them to crit is an acceptable counterbalance.
Can you twin booming blade?
Yes, Booming Blade can be twinned, because a range of Self is not the same thing as a range of Self (5-foot radius)
Is the blade flourish tied to the damage roll?
The counterargument is that the die (Blade Flourish) is not tied to the damage roll; it’s an addition that’s applied after you figure the attack’s ability to land. As with all damage dice that are added to a damage roll, the extra damage from Blade Flourish is doubled (see this Q&A for more details).
When to use blade flourish in College of Swords?
The College of Swords bard ‘s Blade Flourish feature (XGtE, p. 15) says, in part: Whenever you take the Attack action on your turn, […] if a weapon attack that you make as part of this action hits a creature, you can use one of the following Blade Flourish options of your choice.
Is there a difference between blade flourish and blade flourish?
There is no difference in the wording between Blade Flourish and other similar abilities. Here is Blade Flourish: You can expend one use of your Bardic Inspiration to cause the weapon to deal extra damage to the target you hit.
Is the AC of defensive flourish the same as Blade flourish?
Even though the same number is, for example, used for the AC of Defensive Flourish, you only add the extra roll to damage. In the comments on the question, you also mentioned that part of the rationale for the contrary argument is that you declare Blade Flourish before the attack roll. This is not the case.
