5th Edition Spells – Booming Blade

Booming Blade

Sorcerer, Warlock, Wizard - Cantrip Level Spell

School: Evocation
Casting Time: 1 Action
Range: 15 ft
Components: Verbal and Material
Duration: 1 Round
Attack/Save: Melee
Reference: SCAG 143

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails. On a hit, the target suffers the attack’s normal effects, and it becomes sheathed in booming energy until the start of your next turn. If the target willingly moves before then, it immediately takes 1d8 thunder damage, and the spell ends.

This spell’s damage increases when you reach higher levels. At 5th level, the melee attack deals an extra 1d8 thunder damage to the target, and the damage the target takes for moving increases to 2d8. Both damage rolls increase by 1d8 at 11th level and 17th level.

(NOTE: For some reason, people interested in Booming Blade are also interested in Green Flame Blade, found here)

My Comments: I’ve heard people say this spell is over-powered (OP) for a cantrip. I don’t think I agree. Cast by a low-level caster, it’s not that great. It seems to me that you really have to work it to make it worthwhile. For one, your caster has to get all up in the melee, make an attack and actually hit, and then the target has to willingly move for the spell to take effect.

If you’re already in range, why should the target move when it could just stay there and smack you?

Also, it’s always important to remember the downside of Thunder-damage spells- They’re noisy. This is not a sneaky spell.

But then… at 5th level, things change. The spell does extra damage if they don’t move and even more extra damage if they do. The real value though comes in the combos. I’ve avoided talking about combos just to keep these posts simple, but I guess it’s time to break that tradition.

I thought maybe an Eldritch Knight could make good use of it but then realized the spell takes a whole action, so it isn’t really that great for characters with multiple attacks.

Warlock, Pact of the Blade? Sorcerer, use sorcery points to Twin spell maybe? Nah, it’s not really working for me. To me, the best class to use this would be the Arcane Trickster. Only, it’s not very sneaky…

(read all the comments for some good insights from readers on this cantrip)

Herek had been twisting through the dark, smelly corridors of the low-town market for what seemed like hours and his pursuers grew in number with each passing minute. They would have to catch him eventually.

His little tricks were running out and he was down to one he had been avoiding. Now, with that hulking barbarian half-breed the tavern had hired standing in the alley sniffing at the air, he knew the chase was coming to a close. he counted to four, quietly said “kra-hashek!” and then burst out of his hiding spot. He stabbed deeply into the tavern guard and rolled away and dashed back down the alley as a boom of thunder rang out, drowning out even the pig-nose barbarian’s scream.

Booming blade cantrip spell image by Tiago Alexandre

Booming Blade cantrip spell image by the brilliant Tiago Alexandre. Click the image to see more.

The guard turned, her eyes lit with fury, and spotted Herek down the alley. As she started her enraged charge a second crackling boom sounded and the barbarian screamed again, threw her arms out and then fell to the ground.

Herek sighed. That’s one down and at least five more out there and now they all knew exactly where to find him. “Oh well,” he thought, “might as well make them work for it.”

He sprinted forward, planted one boot on the barbarian’s thick back and leaped upward. His hand grasped the bottom of the balcony above and he pulled hard, grabbed the railing above and then twisted himself up to stand on the balcony in one swift burst of acrobatics. He lined up his path to the rooftop just as two more guards came around the corner and saw their fallen comrade.

How to get booming blade: This spell is found in the Sword Coast Adventure’s Guide.

[pssst… want to draw a card from The Deck of Many Things?]

Dave Goff

Writing and creating in my spare time to avoid going crazy in this mad, mad, world. Check out some of my materials on DMsGuild and let me know what you think! subscribe to keep up with new posts and leave comments to keep the conversation going.

17 Comments

  1. rakaduanii on April 3, 2018 at 8:36 pm

    Well say you have a fighter, he/she takes magic initiate and uses a whip,(i am specifically thinking my dex based archer battlemaster). Then you have a booming bladed weapon with reach and superiority dice(like pushing attack). Thats a nice little combo after level 5. It may not be multiple attacks but it does make for some battlefield control and extra damage. So situational but nice

    • Dave Goff on April 3, 2018 at 9:52 pm

      I like your example not just for the crunchy numbers and strategy, but for the Role-playing flavor. The idea of a booming whip is really quite appealing to me. Nice one!

    • Josh on November 6, 2018 at 4:43 pm

      You would have to add spell sniper feat as well fyi, otherwise Booming Blade is only 5ft range.

      • foolishboy on November 6, 2018 at 5:19 pm

        Good point, Josh! It’s easy to forget that it’s 5ft from the caster, not the weapon.
        Man… can you imagine booming arrows? That would be fun, and ridiculous. 🙂



  2. Chaosrex on April 6, 2019 at 8:47 pm

    This + War caster, Lets you make Ao with a Cantrip, Use this Cantrip and since the mob is moving( thats why you got an AO), it will take extra damage.

  3. Maxwell on April 12, 2019 at 4:33 pm

    All of you have missed the biggest combo of all, high elf Swashbuckler rogue. It gets you a free wizard cantrips and you can (and should) pick this one. I call it hit-and-run-rogue, and that’s a literal description. As long as you launch an attack (which this cantrip requires you to do) your movement causes no opportunity attacks, meaning you can immediately move away and force them to chase you. I once went into a 1v1 with a fully con barbarian, and killed him in 5-6 turns using this tactic.

    • mic on January 21, 2020 at 3:57 am

      You can use the same tactic with any character using the mobility feat which creates the same no opportunity attack scenario that a Swashbuckler would. Of course you’d lose the sneak attack damage that a Swashbuckler would do but there might be compensating factors in whatever other class you’re playing.

  4. Kirk on January 5, 2020 at 10:26 pm

    This spell is written incorrectly. “If the target moves before then.” The action of attacking is moving. It doesn’t state move out of it’s current square. Also even if you follow the idea of how it works it’s idiotic. You can swing a 2 handed sword with all your might and nothing happens. But slowing back away and bang. You move more with the first action. Seriously WTF Wizards of the Coast.

    • mic on January 21, 2020 at 3:52 am

      The spell description is using the game’s definition of “movement” which is anything that moves you around the battlefield. I agree it makes for a wonky spell description but it does make sense in a way.

    • Jeff w on January 30, 2020 at 11:48 am

      The game’s definition of “movement” is based off the battle grid/hex map.
      Not “movement” like you lifted your arm.

      Its ok this is a common misunderstanding for non-native english speakers like yourself.

    • Jeff W on January 30, 2020 at 11:53 am

      This is why GFB is almost a better choice by the numbers, unless you have a big “team work” battle master in your party. encounter after encounter, GFB will outpace BB slightly, unless extreme care is spend “maximizing” BB.
      But if BB is “help” to be effective, it is WAY BETTER that GFB

  5. Mags on March 11, 2020 at 2:27 am

    People are sleeping on the tempest cleric/magic initiate (wizard)feat. Get booming blade and a few other useful spells (summon familiar and message is what I took) eventually you can use this to scale your damage as the extra damage die comes in when other classes get their second attack (clerics only ever get one attack per action) and as part of the tempest cleric channel divinity you can choose to deal Max damage when dealing lightning or thunder damage (great for when you roll that natural 20)

    Then at 6th level you push creatures 10ft away when dealing lightning or thunder damage. this synergizes well with the second part of booming blade; fighting multiple enemies? Easy, push one back while you your party picks of the remaining combatants, if the DM decides that enemy you pushed back is desperately needed back in the melee it will have to take the damage for moving. If not you can pretty reliably keep the most powerful melee foe from combat.

  6. Dennis on March 28, 2020 at 12:44 am

    At level 7+ the Eldritch Knight can cast a cantrip and make a weapon attack as a bonus action, if the cantrip is Booming Blade or Green Flame Blade that adds a second (melee) weapon attack. Level 7 -10 the cantrip effect is a pure bonus. Level 11+: if there’s a second enemy within 5 feet of you target, Green Flame Blade is probably better; if the Eldritch Knight is tanking and wants to prevent the opponent from moving Booming Blade is better; Otherwise, just make 3 normal attacks.

    The War Caster feat allows casting a spell that meets certain conditions for a Opportunity Attack, Booming Blade meets those conditions but Green Flame Blade does not (it has multiple targets). For a character, like an Eldritch Knight, with strong melee attacks and a melee ability higher than their spell casting ability, Booming Blade looks pretty good compared to, say, Shocking Grasp.

    Now add the Polearm Master feat to make Opportunity Attacks on approaching enemies, and the Eldritch Knight gets *really* dangerous.

    • Dennis on April 10, 2020 at 12:09 pm

      Doh. I missed that using BB with a reach weapon would require the Spell Sniper feat. In addition to War Caster and Polearm Master. Which is quite the feat tax…

      Polearm Master includes the quarterstaff and has been errata’d to include the spear. Both are versatile weapons without reach. And though it might intuitively seem this should only apply when wielding them two handed the feat doesn’t mention this, so shield and spear, or shield and quarterstaff, would be viable and wouldn’t require Spell Sniper.

      But it requires very specific, and unusual builds, like mine above or the High Elf / Magic Initiate Duellist Rogue someone described above to gain significant advantage from BB.

      For the Eldritch Knight without War Caster + Polearm Master shenanigans, Green Flame Blade is probably better – opportunity attacks aren’t frequent enough in 5e to make War Caster alone enough to justify BB for sub-class that gets very few cantrips.

  7. Dan D. on April 10, 2020 at 10:47 am

    BB would be a lot more useful if its range was equal to the melee weapon used to cast it. IMHO it would be a reasonable, logically sound house rule. That way you could use a weapon with reach and force the movement damage if your opponent tries to close with you. Otherwise, I agree, it really isn’t a great choice for anyone that has access to multiple attacks. (I made the mistake of taking it with my Pact of the Blade Warlock, and now I regret the wasted cantrip slot).

    • Dennis on April 10, 2020 at 12:21 pm

      You could change the range for BB and Green Flame Blade to touch and reword them to the target the weapon which then delivers the effect.

      • Dan D. on April 10, 2020 at 2:56 pm

        Works for me. If you keep it to melee attacks, so you can’t use it with a ranged attack, I don’t think it makes it OP.



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