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DnD 5e - Melee Cantrips vs. Extra Attack

Last Updated: March 22nd, 2019

Sword Coast Adventurer's Guide introduced several notable cantrips. Among them were Booming Blade and Green-Flame Blade, which notably combine casting a spell and swinging a weapon. This is great thematically for "gish" characters like eldritch knights, spellsings, and hexblades, but exactly how effective these spells are is difficult to measure without digging into the math.

To cater to gish builds (and to other characters considering Magic Initiate), we'll cover a select handful of cantrips which are used in melee. For the purposes of this article, we'll limit ourselves to cantrips which either affect creatures within 5 ft. or which apply to creatures which we can reach with a weapon.

Covered Cantrips

  • Booming Blade
  • Green-Flame Blade
  • Shocking Grasp
  • Sword Burst / Thunderclap

Base Assumptions

First, we will assume that all attacks will hit and all cantrips won't be resisted by the targets. This is an absurd assumption in a real game, but it dramatically simplifies our math. We can reasonably assume that players will hit with attacks 60% of the time based on the Attack vs. AC progression, but it;s harder to assess the reliability of cantrips like Sword Burst because saving throws range so widely between creatures.

Second, we will assume that you begin with a 16 in the ability score which you use to attack, and that you spend your first two ability score increases on that ability score. This means that you will have a +3 bonus at 1st level, a +4 bonus at 4th level, and a +5 bonus at 8th level.

Third, we will assume that the non-spellcaster in our example is a single-class fighter. Therefore, we can assume that the example character will get Extra Attack at 5th level and so on as indicated in the Fighter class table. We will list the Fighter's weapon damage in a separate column to distinguish the Fighter's additional attacks from those of other classes like Barbarian and Paladin which get fewer attacks.

Fourth, we will assume that the example spellcaster will have no abilities which add additional damage to cantrips or to weapon attacks. There are several such abilities, but the intent is to provide general guidance. As such, we will omit options like Fighting Style or Potent Cantrip.

Fifth, we will totally ignore critical hits. Between things like the Half-Orc's Save Attacks and abilities like Improved Critical, there are too many variables which are too specific to consider without making this article too complicated to be useful.

Targets

Much of the time, you will be attacking single targets. However, some options shine while you attack a single target, while others excel when you're facing multiple targets. To show the range here, we will assess damage comparisons when facing up to 4 targets.

Results

The tables below detail damage at a subset of the level range from 1-20. Levels at which damage does not change are omitted for brevity. Damage is the average of the total damage deal (so 1d6 damage to two creatures is 7 damage; 3.5 avg. damage to two targets).

The columns in the tables below are as follows:

  • Martial (1h): A martial character such as a barbarian or paladin using a one-handed weapon like a longsword. At 5th level, Extra Attack adds a 2x multiplier.
  • Fighter (1h): A fighter using a one-handed weapon like a longsword. Steps of Extra Attack add an appropriate multiplier at 5th, 11th, and 20th level.
  • Fighter (2h): A martial character such as a barbarian or paladin using a greatsword. At 5th level, Extra Attack adds a 2x multiplier.
  • Fighter (2h): A fighter using a greatsword. Steps of Extra Attack add an appropriate multiplier at 5th, 11th, and 20th level.
  • Booming Blade (1h): Damage dealt by Booming Blade to a single target that does not move to trigger the secondary damage while using a one-handed weapon like a longsword.
  • Booming Blade+ (1h+): Damage dealt by Booming Blade with a one-handed weapon if the target moves and triggers the secondary damage.
  • Green-Flame Blade (1h): Damage dealt by Green-Flame Blade while using a one-handed weapon like a longsword. For 2+ targets, it is assumed that the secondary damage is applied to an appropriate target and the damage is included in the total.
  • Booming Blade (2h): Damage dealt by Booming Blade to a single target that does not move to trigger the secondary damage while using a two-handed weapon like a greatword.
  • Booming Blade (2h+): Damage dealt by Booming Blade with a two-handed weapon if the target moves and triggers the secondary damage.
  • Green-Flame Blade (2h): Damage dealt by Green-Flame Blade while using a two-handed weapon like a greatsword. For 2+ targets, it is assumed that the secondary damage is applied to an appropriate target and the damage is included in the total.
  • Shocking Grasp: Damage dealt by Shocking Grasp.
  • Sword Burst: Damage dealt by the Sword Burst cantrip. Thunderclap's damage is the same so we'll treat them as the same.

1 Target

Against single targets, two-handed weapons always do better than two-handed weapons with a cantrip. The more interesting comparison is between one-handed weapons and Booming Blade with a one-handed weapon. If you can trigger the secondary damage from Booming Blade, it will consistently deal more damage than a weapon, regardless of the number of attacks made.

However, the gap is small enough that even minor damage bonuses like those from Fighting Style (Dueling), Rage, or a +1 weapon will all put weapon attacks ahead of cantrips in many cases. Booming Blade does better compared to non-Fighter martial characters who get less attacks, nearly matching the damage output of 2 attacks at 11th level without secondary damage and eventually surpassing it at 17th level.

Comparative damage progression against one target
Martial Characters Cantrips
Level
Martial (1h)
Fighter (1h)
Martial (2h)
Fighter (2h)
Booming Blade (1h)
Booming Blade (1h+)
Green-Flame Blade (1h)
Booming Blade (2h)
Booming Blade (2h+)
Green-Flame Blade (2h)
Shocking Grasp
Sword Burst
1 7.5 (1d8+3) 7.5 (1d8+3) 10 (2d6+3) 10 (2d6+3) 7.5 (1d8+3) 12 (1d8+3+1d8) 7.5 (1d8+3) 10 (2d6+3) 14.5 (2d6+3+1d8) 10 (2d6+3) 4.5 (1d8) 3.5 (1d6)
4 8.5 (1d8+4) 8.5 (1d8+4) 11 (2d6+4) 11 (2d6+4) 8.5 (1d8+4) 13 (1d8+4+1d8) 8.5 (1d8+4) 11 (2d6+4) 15.5 (2d6+4+1d8) 11 (2d6+4) 4.5 (1d8) 3.5 (1d6)
5 17 (1d8+4 x2) 17 (1d8+4 x2) 22 (2d6+4 x2) 22 (2d6+4 x2) 13 (1d8+4+1d8) 22 (1d8+4+1d8+2d8) 13 (1d8+4+1d8) 15.5 (2d6+4+1d8) 24.5 (2d6+4+1d8+2d8) 15.5 (2d6+4+1d8) 9 (2d8) 7 (2d6)
8 19 (1d8+5 x2) 19 (1d8+5 x2) 24 (2d6+5 x2) 24 (2d6+5 x2) 14 (1d8+5+1d8) 23 (1d8+5+1d8+2d8) 14 (1d8+5+1d8) 16.5 (2d6+5+1d8) 25.5 (2d6+5+1d8+2d8) 16.5 (2d6+5+1d8) 9 (2d8) 7 (2d6)
11 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 18.5 (1d8+5+2d8) 32 (1d8+5+2d8+3d8) 18.5 (1d8+5+2d8) 21 (2d6+5+2d8) 34.5 (2d6+5+2d8+3d8) 21 (2d6+5+2d8) 13.5 (3d8) 10.5 (3d6)
17 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 23 (1d8+5+3d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 25.5 (2d6+5+3d8) 18 (4d8) 14 (4d6)
20 19 (1d8+5 x2) 38 (1d8+5 x4) 24 (2d6+5 x2) 48 (2d6+5 x4) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 23 (1d8+5+3d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 25.5 (2d6+5+3d8) 18 (4d8) 14 (4d6)

2 Targets

Very little changes when you move to 2 targets. Green-Flame Blade can no do as much damage as Booming Blade, but it falls into the same narrow lead that Booming Blade had over straight weapon attacks.

Comparative damage progression against two targets
Martial Characters Cantrips
Level
Martial (1h)
Fighter (1h)
Martial (2h)
Fighter (2h)
Booming Blade (1h)
Booming Blade (1h+)
Green-Flame Blade (1h)
Booming Blade (2h)
Booming Blade (2h+)
Green-Flame Blade (2h)
Shocking Grasp
Sword Burst
1 7.5 (1d8+3) 7.5 (1d8+3) 10 (2d6+3) 10 (2d6+3) 7.5 (1d8+3) 12 (1d8+3+1d8) 12 (1d8+3+1d8) 10 (2d6+3) 14.5 (2d6+3+1d8) 14.5 (2d6+3+1d8) 4.5 (1d8) 7 (1d6 x2)
4 8.5 (1d8+4) 8.5 (1d8+4) 11 (2d6+4) 11 (2d6+4) 8.5 (1d8+4) 13 (1d8+4+1d8) 13 (1d8+4+1d8) 11 (2d6+4) 15.5 (2d6+4+1d8) 15.5 (2d6+4+1d8) 4.5 (1d8) 7 (1d6 x2)
5 17 (1d8+4 x2) 17 (1d8+4 x2) 22 (2d6+4 x2) 22 (2d6+4 x2) 13 (1d8+4+1d8) 22 (1d8+4+1d8+2d8) 22 (1d8+4+1d8+2d8) 15.5 (2d6+4+1d8) 24.5 (2d6+4+1d8+2d8) 24.5 (2d6+4+1d8+2d8) 9 (2d8) 14 (2d6 x2)
8 19 (1d8+5 x2) 19 (1d8+5 x2) 24 (2d6+5 x2) 24 (2d6+5 x2) 14 (1d8+5+1d8) 23 (1d8+5+1d8+2d8) 23 (1d8+5+1d8+2d8) 16.5 (2d6+5+1d8) 25.5 (2d6+5+1d8+2d8) 25.5 (2d6+5+1d8+2d8) 9 (2d8) 14 (2d6 x2)
11 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 18.5 (1d8+5+2d8) 32 (1d8+5+2d8+3d8) 32 (1d8+5+2d8+3d8) 21 (2d6+5+2d8) 34.5 (2d6+5+2d8+3d8) 34.5 (2d6+5+2d8+3d8) 13.5 (3d8) 21 (3d6 x2)
17 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 28 (4d6 x2)
20 19 (1d8+5 x2) 38 (1d8+5 x4) 24 (2d6+5 x2) 48 (2d6+5 x4) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 28 (4d6 x2)

3 Targets

3 targets is where Sword Burst starts to edge out other options. The gap in damage fluctuates depending on your level, but sword burst remains consistently more effective.

Comparative damage progression against three targets
Martial Characters Cantrips
Level
Martial (1h)
Fighter (1h)
Martial (2h)
Fighter (2h)
Booming Blade (1h)
Booming Blade (1h+)
Green-Flame Blade (1h)
Booming Blade (2h)
Booming Blade (2h+)
Green-Flame Blade (2h)
Shocking Grasp
Sword Burst
1 7.5 (1d8+3) 7.5 (1d8+3) 10 (2d6+3) 10 (2d6+3) 7.5 (1d8+3) 12 (1d8+3+1d8) 12 (1d8+3+1d8) 10 (2d6+3) 14.5 (2d6+3+1d8) 14.5 (2d6+3+1d8) 4.5 (1d8) 10.5 (1d6 x3)
4 8.5 (1d8+4) 8.5 (1d8+4) 11 (2d6+4) 11 (2d6+4) 8.5 (1d8+4) 13 (1d8+4+1d8) 13 (1d8+4+1d8) 11 (2d6+4) 15.5 (2d6+4+1d8) 15.5 (2d6+4+1d8) 4.5 (1d8) 10.5 (1d6 x3)
5 17 (1d8+4 x2) 17 (1d8+4 x2) 22 (2d6+4 x2) 22 (2d6+4 x2) 13 (1d8+4+1d8) 22 (1d8+4+1d8+2d8) 22 (1d8+4+1d8+2d8) 15.5 (2d6+4+1d8) 24.5 (2d6+4+1d8+2d8) 24.5 (2d6+4+1d8+2d8) 9 (2d8) 21 (2d6 x3)
8 19 (1d8+5 x2) 19 (1d8+5 x2) 24 (2d6+5 x2) 24 (2d6+5 x2) 14 (1d8+5+1d8) 23 (1d8+5+1d8+2d8) 23 (1d8+5+1d8+2d8) 16.5 (2d6+5+1d8) 25.5 (2d6+5+1d8+2d8) 25.5 (2d6+5+1d8+2d8) 9 (2d8) 21 (2d6 x3)
11 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 18.5 (1d8+5+2d8) 32 (1d8+5+2d8+3d8) 32 (1d8+5+2d8+3d8) 21 (2d6+5+2d8) 34.5 (2d6+5+2d8+3d8) 34.5 (2d6+5+2d8+3d8) 13.5 (3d8) 31.5 (3d6 x3)
17 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 42 (4d6 x3)
20 19 (1d8+5 x2) 38 (1d8+5 x4) 24 (2d6+5 x2) 48 (2d6+5 x4) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 42 (4d6 x3)

4 Targets

At 3 targets Sword Burst was the winner, and 4 targets puts Sword Burst even further ahead of other options.

Comparative damage progression against three targets
Martial Characters Cantrips
Level
Martial (1h)
Fighter (1h)
Martial (2h)
Fighter (2h)
Booming Blade (1h)
Booming Blade (1h+)
Green-Flame Blade (1h)
Booming Blade (2h)
Booming Blade (2h+)
Green-Flame Blade (2h)
Shocking Grasp
Sword Burst
1 7.5 (1d8+3) 7.5 (1d8+3) 10 (2d6+3) 10 (2d6+3) 7.5 (1d8+3) 12 (1d8+3+1d8) 12 (1d8+3+1d8) 10 (2d6+3) 14.5 (2d6+3+1d8) 14.5 (2d6+3+1d8) 4.5 (1d8) 14 (1d6 x4)
4 8.5 (1d8+4) 8.5 (1d8+4) 11 (2d6+4) 11 (2d6+4) 8.5 (1d8+4) 13 (1d8+4+1d8) 13 (1d8+4+1d8) 11 (2d6+4) 15.5 (2d6+4+1d8) 15.5 (2d6+4+1d8) 4.5 (1d8) 14 (1d6 x4)
5 17 (1d8+4 x2) 17 (1d8+4 x2) 22 (2d6+4 x2) 22 (2d6+4 x2) 13 (1d8+4+1d8) 22 (1d8+4+1d8+2d8) 22 (1d8+4+1d8+2d8) 15.5 (2d6+4+1d8) 24.5 (2d6+4+1d8+2d8) 24.5 (2d6+4+1d8+2d8) 9 (2d8) 28 (2d6 x4)
8 19 (1d8+5 x2) 19 (1d8+5 x2) 24 (2d6+5 x2) 24 (2d6+5 x2) 14 (1d8+5+1d8) 23 (1d8+5+1d8+2d8) 23 (1d8+5+1d8+2d8) 16.5 (2d6+5+1d8) 25.5 (2d6+5+1d8+2d8) 25.5 (2d6+5+1d8+2d8) 9 (2d8) 28 (2d6 x4)
11 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 18.5 (1d8+5+2d8) 32 (1d8+5+2d8+3d8) 32 (1d8+5+2d8+3d8) 21 (2d6+5+2d8) 34.5 (2d6+5+2d8+3d8) 34.5 (2d6+5+2d8+3d8) 13.5 (3d8) 42 (3d6 x4)
17 19 (1d8+5 x2) 28.5 (1d8+5 x3) 24 (2d6+5 x2) 38 (2d6+5 x3) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 56 (4d6 x4)
20 19 (1d8+5 x2) 38 (1d8+5 x4) 24 (2d6+5 x2) 48 (2d6+5 x4) 23 (1d8+5+3d8) 41 (1d8+5+3d8+4d8) 41 (1d8+5+3d8+4d8) 25.5 (2d6+5+3d8) 43.5 (2d6+5+3d8+4d8) 43.5 (2d6+5+3d8+4d8) 18 (4d8) 56 (4d6 x4)

Conclusions: Are melee cantrips better than normal weapon attacks?

Yes, but only if you get their full effects.

Melee cantrips are be better than regular weapon attacks in the precise circumstances where they work best: Booming Blade is great if you can trigger the secondary damage, Green-Flame Blade is great if there's a valid secondary target, and Sword Burst is good against 3 or more targets. In all other cases, straight weapon attacks are more effective until roughly 17th level when the damage from the initial Booming Blade/Green-Flame Blade attack can outpace normal weapon damage with two attacks.

Fighters, thanks to their high number of attacks, will always outpace the damage from Booming Blade and Green-Flame Blade (unless you include War Magic; see below). This math also doesn't account for other damage bonuses from things like Rage, magic items, and Improved Divine Smite, all of which tip the balance back in favor of normal attacks.

Exceptions

I can think of two exceptions to the above assessment:

First: Rogues. Rogues never get Extra Attack. Melee cantrips present a linear damage increase since Booming Blade and Green-Flame Blade can deliver Sneak Attack, and both a single attack and casting either cantrip takes an action. If the attack hits, the Rogue is left with their bonus action to Disengage, potentially forcing enemies to suffer the bonus damage from Booming Blade to chase them.

Second: Eldritch Knights with War Magic. War Magic allows you to make an additional attack as a bonus action after casting a cantrip (also leveled spells at higher levels, but that's not the point of this article). This means that your cantrip+attack combos will always deal more damage than a non-Fighter martial class's two weapon attacks. Even in the case of other damage bonuses like Hunter's Mark or Hex, you're probably still ahead. Even compared to a Fighter's maximum of 4 attacks, War Caster will still let you exceed the non-caster Fighter's damage by a fair margin if you can trigger the secondary damage.

Levels 1-6 are omitted from the table below because Eldritch Knights get War Magic at 7th level.

Fighter Damage vs. War Magic Damage
Level
Fighter (1h)
Fighter (2h)
War Magic (1h)
War Magic (1h+)
War Magic (2h)
War Magic (2h+)
7 17 (1d8+4 x2) 22 (2d6+4 x2) 21.5 (1d8+4+1d8+1d8+4) 30.5 (1d8+4+1d8+2d8+1d8+4) 26.5 (2d6+4+1d8+2d6+4) 35.5 (2d6+4+1d8+2d8+2d6+4)
8 19 (1d8+5 x2) 24 (2d6+5 x2) 23.5 (1d8+5+1d8+1d8+5) 32.5 (1d8+5+1d8+2d8+1d8+5) 28.5 (2d6+5+1d8+2d6+5) 37.5 (2d6+5+1d8+2d8+2d6+5)
11 28.5 (1d8+5 x3) 38 (2d6+5 x3) 28 (1d8+5+2d8+1d8+5) 41.5 (1d8+5+2d8+3d8+1d8+5) 33 (2d6+5+2d8+2d6+5) 46.5 (2d6+5+2d8+3d8+2d6+5)
17 28.5 (1d8+5 x3) 38 (2d6+5 x3) 32.5 (1d8+5+3d8+1d8+5) 50.5 (1d8+5+3d8+4d8+1d8+5) 37.5 (2d6+5+3d8+2d6+5) 55.5 (2d6+5+3d8+4d8+2d6+5)
20 38 (1d8+5 x4) 48 (2d6+5 x4) 32.5 (1d8+5+3d8+1d8+5) 50.5 (1d8+5+3d8+4d8+1d8+5) 37.5 (2d6+5+3d8+2d6+5) 55.5 (2d6+5+3d8+4d8+2d6+5)