26 Jan Booming Blade 5e D&D Guide 
Here we take a look at Booming Blade, a damage boosting melee cantrip. It holds promise for any full caster and really shines when paired with an array of subclasses.
Booming Blade 5e
The rules for Booming Blade are found in The Sword Coast Adventurers Guide and Tasha’s Cauldron of Everything.
Casting Time: 1 Action
Range: Self (5-Foot Radius)
Components: V, M (A melee weapon worth at least 1sp.)
Duration: 1 Round
You brandish the weapon used in the spells casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapons normal effects and then becomes sheathed in booming energy until the start of your next turn. If the target willingly moves 5 feet or more before then, the target takes 1d8 thunder damage, and the spell ends.
This spell’s damage increases when you reach certain levels. At 5th level, the melee attack deals an extra 1d8 thunder damage to the target on a hit, and the damage the target takes for moving increases to 2d8. Both damage rolls increase by 1d8 at 11th level (2d8 and 3d8) and again at 17th level (3d8 and 4d8).
The rules for the Booming Blade cantrip show it is a bit unconventional, provided it utilizes a melee weapon attack through a spell. The key to remember here is this is a Spell Action, not an Attack Action, follow the rules as such.
Is Booming Blade Good?
Booming Blade increases the damage output for any weapon on a single attack. This can dramatically affect a caster’s usefulness outside of using spells that require slots. Since it is a damage cantrip, it levels up nicely. The additional damage dealt when an enemy willingly moves is just a bonus reason to use the spell.
Booming Blade deals thunder damage, and while not the rarest resistance type, it is not as common as fire or lightning. Beyond that, even a creature that has resistance to thunder still takes the normal weapon damage. This means that character classes that have only one attack can do increased damage on every attack and bonus damage if the creature moves more than 5 feet willingly.
What Classes get Booming Blade?
Booming Blade is an evocation cantrip on the Wizard, Sorcerer, and Warlock spell lists. This makes the spell serviceable for the general caster. It does bonus damage on any melee attack. The problem is that generally, if a caster is making a melee attack, the situation is dire.
The Eldritch Knight is a good option, as is the hex-based Warlock, but the real master of this spell is the Arcane Trickster Rogue. Outfitted with a 1d8 damage rapier, an Arcane Trickster using Booming Blade does 2d8 damage for an attack at level 1.
The benefit of this class combo only gets better as the character levels up. The damage increases per the standard cantrip rate, meaning additional damage at 5th,11th, and 17th levels. Also, at level 5, the target takes 2d8 thunder damage if it moves 5 feet willingly. By the way, it stacks on sneak attack.
Booming Blade: Optimized for Combat
As stated above, any class can take Booming Blade and see a benefit, but the best use of the Evocation Cantrip belongs to the Arcane Trickster Rogue. While thunder damage is not stealthy by any means, the spell was practically made for the rogue class.
The Rogue class gets Sneak Attack at 1st level and the Cunning Action ability at 2nd level. Cunning Action allows them to use a bonus action to hide, dash, or disengage. At 2nd level, the rogue outfitted above does 2d8 damage (rapier 1d8+Booming Blade 1d8) plus sneak attack (if applicable, 1d6) if they use the spell and add 1d8 for Booming Blade if the target moves 5 feet or more. This allows the rogue to match any other class in terms of damage, if not outright best them.
At 5th level, Booming Blade adds 2d8 damage if the target moves more than 5 feet, plus the regular cantrip increase to 2d8. An Arcane Trickster Rogue at level 5 has a combat turn damage of 2d8 from Booming Blade + 1d8 from the rapier + 3d6 from sneak attack (if applicable) + 2d8 from the target of Booming Blade moving.
A clever rogue will move into melee range with a creature who is engaged with the rogue’s ally and attack, hitting for 3d8+3d6 damage. Then disengage, hoping to draw the monster toward the rogue causing the monster to take the additional 2d8 damage.
Booming Blade: Sword Coast vs. Tasha’s
- A few updates were made to Booming Blade with the release of Tasha’s Cauldron of Everything. The rules here are the most recent presented in TCE. Some of the notable changes were:
- Range changed from 5 feet to “self (5-foot radius).”
- The spell cannot be Twin Spelled via metamagic due to the new range of self.
- The spell can be cast using the War Caster Feat.
- The spell no longer works with the Spell Sniper Feat as the spell has a range of self and cannot be doubled.
- A Pact Weapon can be used with the spell since the conjured weapon simulates the value of a real weapon.
Cantrips are about as easy to get as hit points for a wizard, so picking them can be tricky. Booming Blade is about as good as you can get in terms of damage at close range. It should definitely be considered if you are a caster who finds themselves too close for comfort with enemies often.