Can You Stack Green-Flame Blade and Booming Blade?
The short and definitive answer is no, you cannot stack the effects of Green-Flame Blade and Booming Blade. You cannot have both cantrips’ effects active simultaneously on a single attack, nor can you have one active on one attack and another active on the same target during the same turn. These two popular cantrips, while often used in tandem by gish-type characters, are mutually exclusive in their application. While they share similar mechanics and goals, they are designed to be used as distinct options, not cumulative ones. They represent different ways to enhance a melee attack. You cannot, for instance, cast both cantrips on the same turn. You can only cast one cantrip per turn.
Understanding the Mechanics
Before diving deeper, let’s break down what these cantrips actually do:
Green-Flame Blade
Green-Flame Blade is a cantrip that combines a melee attack with fire damage. As part of the action used to cast the spell, you make a melee attack with a weapon. If the attack hits, it deals the weapon’s normal damage, and then adds extra fire damage. Crucially, if there’s another creature within 5 feet of your target, the flames jump to that creature, dealing additional fire damage.
Booming Blade
Booming Blade also combines a melee attack with extra damage, but in a different way. As part of the action used to cast the spell, you make a melee attack with a weapon. If the attack hits, it deals the weapon’s normal damage. However, the special effect of Booming Blade is that the target then suffers extra thunder damage if it moves before the start of your next turn.
Why They Don’t Stack
The core reason they don’t stack lies in their spellcasting mechanics and the action economy of D&D 5e.
- One Cantrip Per Turn: You are generally limited to casting one cantrip per turn. Even if you could use multiple actions (e.g. Action Surge or Quickened Spell), each application of these cantrips involves making a melee attack as a part of the casting, and you are ultimately bound by the single cantrip limitation.
- Specific Casting Requirement: Both cantrips require you to make a melee attack as part of the casting of the spell. You are not enhancing an existing weapon attack but rather using your action to cast a spell that includes an attack. These spells have a specific action type of cast a spell, not an attack action.
How to Use Them Effectively
While you can’t combine them, both Green-Flame Blade and Booming Blade are extremely valuable. The key lies in understanding each spell’s niche.
- Green-Flame Blade is excellent in situations where you can reliably trigger the secondary damage. It is highly effective in combat scenarios with multiple enemies grouped together.
- Booming Blade is better used to control the battlefield, punishing enemies that try to move away from you. It’s great against highly mobile enemies, as its damage trigger relies on enemy movement and does not require you to use your bonus action.
When to choose which cantrip
- For damage: If you are surrounded by a few enemies and want to get the most damage, Green Flame Blade is optimal. The added damage on the second target can quickly increase your damage output.
- For single target control: When fighting a single hard-hitting enemy that needs to be kept in place, Booming Blade is a fantastic choice. It discourages movement and can deal a large amount of damage.
Frequently Asked Questions (FAQs)
Here are some related FAQs about Booming Blade and Green-Flame Blade:
1. Can an Eldritch Knight use Green-Flame Blade and Multiattack?
No. As a general rule, the Green-Flame Blade and Booming Blade spells are not compatible with the standard Multiattack feature, as casting these cantrips uses the cast a spell action, not the attack action. You are making a melee attack as part of the spell, not as part of the attack action. At level 7, the Eldritch Knight gains the ability to make a weapon attack as a bonus action after casting a cantrip, but still cannot take the full attack action.
2. Can a Bladesinger use Booming Blade and Multiattack?
Yes, but not in the way you might expect. At level 6, the Bladesinger gains the feature Extra Attack. This allows the Bladesinger to make a weapon attack in addition to casting a cantrip in the same turn. Thus, they can cast Booming Blade and then follow up with a standard weapon attack as part of their attack action.
3. Can you dual-wield and use Green-Flame Blade?
No. Two-weapon fighting requires you to take the attack action. Since Green-Flame Blade and Booming Blade require the cast a spell action, you cannot benefit from the bonus action attack granted by two-weapon fighting.
4. Can you use a bonus action spell and Green-Flame Blade?
Yes. Using a bonus action spell (such as Misty Step) and then using your standard action to cast Green-Flame Blade or Booming Blade is perfectly valid. The only restriction is you can only cast one cantrip per turn.
5. Can you twin Green-Flame Blade or Booming Blade?
Green-Flame Blade cannot be twinned. The spell inherently has the ability to target more than one creature (the primary target and a secondary one), preventing it from qualifying for Twinned Spell. However, Booming Blade can be twinned because the spell only targets the creature who takes the primary attack, as its range is technically “Self” not a radius from self.
6. Does Green-Flame Blade work with Shillelagh?
Yes. The weapon you use to make the melee attack in Green-Flame Blade can be under the effect of the spell Shillelagh, allowing you to use your Wisdom modifier for the attack.
7. Does Green-Flame Blade require a second target?
No. The secondary damage of Green-Flame Blade only occurs if there is another creature within 5 feet of your primary target. You can still cast the spell and deal your primary damage, even if there is no secondary target.
8. Can you use Green-Flame Blade with War Caster?
Yes, both Booming Blade and Green-Flame Blade work with the War Caster feat. However, Green-Flame Blade will only trigger an Attack of Opportunity if there is no second target to receive the ‘jump’ damage.
9. Can you stack multiple Booming Blade effects on the same target?
No. The effects of Booming Blade do not stack. If you hit a target multiple times with the spell, they only suffer the extra damage once, if they move. This is a rule of the game and not a limitation of the spell.
10. Can Green-Flame Blade be used with unarmed strikes?
No. Both Green-Flame Blade and Booming Blade specify that they must be used with a melee weapon. Unarmed strikes do not qualify.
11. Does Spell Sniper work with Green-Flame Blade?
Yes. Spell Sniper extends the range of Green-Flame Blade, but not your weapon’s reach. It allows you to use Green-Flame Blade with a reach weapon from a greater distance, increasing its range significantly.
12. Does Polearm Master work with Green-Flame Blade?
No. The bonus action attack from Polearm Master requires the attack action to trigger. Casting Green-Flame Blade is not the attack action, thus the bonus action attack is not triggered.
13. Can you Smite with Green-Flame Blade?
Yes. If you are a Paladin or a Sorcerer-Paladin, you can use a Divine Smite or other smite abilities when making the melee weapon attack part of Green-Flame Blade or Booming Blade.
14. Does Green-Flame Blade give off light?
Yes, when triggered by the Tiefling racial feat, Flames of Phlegethos, Green-Flame Blade produces bright light out to 30 feet and dim light for an additional 30 feet. The flames don’t harm you or your possessions.
15. Can you use Green-Flame Blade with a Shadow Blade?
No. By RAW you cannot combine Green-Flame Blade or Booming Blade with the spell Shadow Blade. Both cantrips specify that you must use a melee weapon worth 1 silver piece. A shadow blade is not such a weapon.
Conclusion
While you cannot stack Green-Flame Blade and Booming Blade, understanding how they function independently is crucial to making smart tactical decisions. Both cantrips remain powerful tools for melee characters, offering unique advantages in different combat scenarios. By understanding the mechanics and limitations of each spell, you can maximize your character’s damage output and battlefield control.