How does the blade flourish feature work?

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… Stack Exchange Network

Is blade flourish good for 2 weapon fighting?

In the cast that you plan on spending your Inspirations to use Blade Flourish, then Two-Weapon Fighting becomes much more viable. However, keep in mind that picking people off the ground with Healing Word might be more important than hitting people for 1d6+Dexterity. The final level 3 ability is Blade Flourish.

Do you declare Blade flourish before or after an attack roll?

In the commentson 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. You choose to use a Blade Flourish option afteryou hit: …if a weapon attack that you make as part of this action hits a creature]

What is the difference between blade flourish and sneak attack?

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. …and here is Sneak Attack: Once per turn, you can deal an extra 1d6 damage to one creature you hitwith an attack…

Is blade flourish tied to the number of damage dice?

Both are effects you declare you are using after you have attacked the enemy, and are thus subject to the critical hit rule, which doubles the number of damage dice. 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.