Booming Blade (BB) spell in DnD 5E explained

A smile blazoned across his face, we watched with curiosity as the party’s Rogue slashed at the Wight with his short sword accompanied by the low rumble of distant thunder. The cut was precise and deep; the wound messier than expected from concussive force accompanying the blade. With practiced ease, he dropped into a defensive stance and strode confidently backwards. It was a tense moment as the undead horror lunged forwards, its hand outstretched towards the Rogue’s throat, the silence was broken in short order by the clatter of thunder as the Wight’s body suddenly crumpled like a used scroll and fell to the ground.

What is Booming Blade?

Booming Blade (BB) is a cantrip that augments your melee attack and is on the Sorcerer, Warlock, and Wizard spell lists. It’s also available to Eldritch Knight Fighters, Arcane Trickster Rogues, and certain races and feats, like the High Elf and Magic Initiate respectively. Originally printed in the SCAG, Booming Blade was reprinted with a slight rules change in TCoE, this change primarily requiring a weapon with a gold value and was errata’ed into the SCAG.

How does Booming Blade work?

When you cast Booming Blade, you can make one melee attack as part of that action. Keep in mind, you only make one attack when casting the spell, even if you have the Extra Attack feature. If the attack hits, the creature is then shrouded in booming energy, and if it willingly moves at least 5ft before the start of your next turn, it takes 1d8 thunder damage. 

At 5th level, the damage the target takes when it moves increases to 2d8, but you also gain 1d8 thunder damage to the attack’s damage. At 11th and 17th level, both the additional attack damage and the movement damage increase by another d8.

Who is Booming Blade best for?

Booming Blade is a great cantrip for anyone who can add damage onto a single attack, can cast it as a bonus action (Quickened Spell metamagic) or reaction (Warcaster feat), or has enhanced mobility to skirmish (e.g. the Mobile feat). If you would have Extra Attack then BB is not particularly good unless; you have a way to hit and run to provoke the additional damage or you are playing a tank and want to stop the enemy ignoring you and attacking the squishy spellcasters hiding behind you.  Some examples of characters that would be able to take advantage of BB:

Fighters – This only really applies to the Eldritch Knight, who can leverage additional damage from the Shadow Blade spell, the Dueling fighting style, and from 7th level make an attack as a bonus action after casting BB. Once you hit 11th level and get a third attack from Extra Attack, BB drops off heavily.

Rogues – Whilst Arcane Tricksters are able to pick this up from their subclass, any other Rogue could get this from a feat, race, or multiclassing. As Rogues rely on Sneak Attack rather than Extra Attack, they aren’t missing out on another attack by casting a spell, and Cunning Action allows them to Disengage as a bonus action to provoke the enemy to chase them and trigger the extra damage. The Swashbuckler is also a good subclass to use BB, as they gain the benefit of disengaging from anyone they make an attack against.

Paladins – This applies more specifically to Sorcerer/Paladin multiclasses, Divine Smite allows you to add a lot of additional damage. And we know how much Paladins love to tack on extra damage!  At higher levels (11th+), it isn’t typically worth it for a single classed Paladin to use Booming Blade instead of Extra Attack, due to Improved Divine Strike.

Sorcerers – Metamagic allows for a couple of neat tricks with BB, you can both use Quickened Spell to attack as a bonus action, but you can use Twinned Spell to attack two creatures within 5ft at once. For skirmishing, they have access to Misty Step, and for adding more damage to the attack itself, Shadow Blade can be used for higher weapon damage.

Wizards – Specifically Bladesingers, as of the TCoE printing (and subsequent errata of the SCAG) Bladesingers can cast a cantrip as part of their Extra Attack feature. This turns Booming Blade into a very ‘no brainer’ choice for a Bladesinger to get as much melee punch as they can (unless they prefer Green Flame Blade, of course).

Hopefully this article made your cantrip choices for your next gish character easier, or to put some extra oomph or should we say, boom, to your attacks. If you enjoyed this article, head on over to our spells section. Good luck on those attack rolls, just don’t forget your ear plugs!