Maximum average damage from a single unarmed strike

Question

What is the maximum average damage that can be delivered by a single unarmed strike from a Dungeons and Dragons 5e character?

A few qualifications for preferred answers:

• The damage must be a direct consequence of the blow itself - no shoving the target into a volcano.
• Average (statistical mean) damage, not maximum assuming lucky rolls - no exploiting one-in-a-billion chances.
• Magic items and spells are permitted, but no resources may be permanently consumed - the character should be able to do the same thing again the next day.
• Legal playable character built with official rules only, Unearthed Arcana excluded. Any Adventurers League allowed content is permitted
• One assistant is permitted. The assistant must follow all the previous restrictions as well.
• Up to ten minutes of preparation is permitted.
• Target is of no specific type

Answer 1

The maximum average damage for a single unarmed strike is 622 damage
(or 478 with unfavorable rulings on Divine Smite and banishing smite, see addendum)

The Character

The character, let's call him Connor, to pull off the most damaging unarmed strike is a level 20 lizardfolk with the following classes:

• Bard (College of Whispers) 16 -------------------------- (for Psychic Blades and spells)
• Cleric (Tempest Domain) 2 ---------------------------- (for Channel Divinity: Destructive Wrath)
• Paladin 2 --------------------------------------------------- (for Divine Smite)

...and the following equipment:

• One insignia of claws
• One set of robes of the archmagi
• One ioun stone of mastery
• Five manuals of gainful exercise
• Five tomes of leadership and influence

...and:

• the Martial Adept feat (gained through the special Training in the Dungeon Master's Guide)
• the Boon of Combat Prowess epic boon (to guarantee that the unarmed strike hits)

The Helper

Our helper, let's call him Hunter, is a level 20 character with the following classes:

• Bard (College of Valor) 15 ------------------- (for Combat Inspiration and spells)
• Sorcerer 3 ------------------------------------- (for Flexible Casting and Heightened Spell Metamagic)
• Cleric (Grave Domain) 2 --------------------- (for Channel Divinity: Path to the Grave)

and the following equipment:

• A small, straight piece of iron
• One set of robes of the archmagi
• One ioun stone of mastery
• Five tomes of leadership and influence

The Preparation

Before the unarmed strike, a handful of buff spells must be cast:

1. Hunter bestows Bardic Inspiration on Connor.
2. Hunter casts shocking grasp on Connor until he hits.
3. Connor casts absorb elements with a 9th level spell slot in response to the lightning damage.
4. Connor casts banishing smite.
5. Hunter casts hold monster on the target using Heightened Spell Metamagic (with the magic items and Metamagic very few monsters even have a minute chance at succeeding, so I will assume the monster fails the save)
6. Connor casts bestow curse on the target with a 5th level spell slot. (see above regarding the magic items that increase the spell save DC)
7. Hunter uses his Channel Divinity: Path to the Grave on the target.

The Strike

After activating the Spell Glyph, Connor's unarmed strike has the following modifiers:

• Bite (uses a d6 and piercing damage)
• 30 Strength from manuals of gainful exercise (+10 modifier)
• Combat Inspiration (1d12 extra piercing damage)
• Martial Adept Maneuver (1d6 extra piercing damage)
• Psychic Blades (8d6 extra psychic damage)
• bestow curse (1d8 extra necrotic damage)
• banishing smite (5d10 extra force damage)
• Divine Smite (5d8 extra radiant damage)
• absorb elements (9d6 extra lightning damage)
• Destructive Wrath (the lightning damage is maximized)
• insignia of claws (+1 damage)
• the target is paralyzed (critical hit)
• the target is vulnerable to the damage (doubled damage)

Resulting in the following calculation:

• 2d6 + 2d12 + 11 piercing damage
• plus 10d8 radiant damage
• plus 10d10 force damage
• plus 18d6 psychic damage
• plus 2d8 necrotic damage
• plus 18d6 maximized lightning damage
• all doubled

This totals to an average damage of:

$$(2*3.5+2*6.5+11 \text{ slashing} +10*4.5 \text{ radiant} + 18*3.5 \text{ psychic}$$ $$+10*5.5 \text{ force}+ 2*4.5 \text{ necrotic} +18*6 \text{ lightning})*2=622\text{ damage}$$

---

Relevant rulings:

• Since Bite includes a natural weapon for use with the unarmed strikes:

  Your fanged maw is a natural weapon, which you can use to make unarmed strikes...

  ...Divine Smite works with the lizardfolk's fanged maw, even though it doesn't work with normal unarmed strikes (see the second section of this answer to a related question for details).

  If your GM still rules that Divine Smite does not work, simply be an aasimar instead and replace the paladin levels with bard levels (with the Boon of High Magic epic boon). Then cast wish replicating the effect of glyph of warding (Spell Glyph: alter self to get a +1 natural weapon that can be used for unarmed strikes) for 574 damage instead. That is still more than enough damage to one-shot the Kraken, so the extra radiant damage is just insult to injury.

• Psychic Blades should work with any unarmed strike, as unarmed strikes are considered weapon attacks

• Banishing Smite should work with any unarmed strike RAW, as even though your weapon is what is crackling with force, the weapon attack is what gets the extra damage, and we've established with the Psychic Blade ruling that unarmed strikes count.

  There is similar RAW instance regarding whether the weapon is the source of the visual effect, but not the damage with the current wording of holy weapon, as explored in this question. However, for our purposes, we are using a natural weapon that is specifically allowed to make unarmed strikes, so banishing smite works anyway.

  If your GM overrules this and deems that a weapon that is not a natural weapon is required, replace banishing smite with wrathful smite for a loss of 96 damage.

Answer 2

319.33, with no questionable divine smites.

You are a Goblin Paladin 2 / Fiend Warlock 14 / Wizard 1 / Monk 3 with Elemental Adept(fire) and Martial Adept (Lunging Attack). Your friend is a Grave Cleric 2 / Divination Wizard 10 / Fighter 2 / Thief Rogue 3 / Valor Bard 3.

In the last 10 minutes, your friend bardically inspired you. Your friend casts Hold Monster (forcing the monster to fail using portent dice if necessary)
Then Action Surges and applies vulnerability with Path to the Grave
Then uses Cunning Action to light a bonfire that you are standing on. You cast Absorb Elements against the fire damage using a 5th level slot.

Your turn:
You cast Wrathful Smite as a bonus action, then use Lunging Attack to punch a guy (automatically critting, so any dice will be multiplied by 2), and using that bardic inspiration die for 1d4 + 1d6 + 1d6 + 1d6 (13*2) damage.
You use Fangs of the Fire Snake for an additional 1d10 (5.5*2) damage.
Absorb Elements deals 5d6 (18.33*2) fire damage.
You Hurl Through Hell for 10d10 (55) psychic damage. Your strength gives 10 additional damage and an Insignia of Claws you have gives 1 more, because you stumbled across the same lost library of Manuals of Gainful Exercise as everyone else here did.
You use Fury of the Small for 20 extra damage as well.

Totaled is 159.66 average damage, doubled by vulnerability for 319.33 average damage.

Answer 3

158 Damage

Assailant

Classes

The base of this build is a Paladin/Rogue multiclass. We're going to be combining the Assassin Rogue's ability to get guaranteed critical hits, and the Paladin's Smite - neither of which require a weapon.

Paladin 13 gives us access to a 4th level Divine Smite (5d8), and to Wrathful Smite (1d6) (the only Smite spell that does not need a weapon). As one of their ASIs we take the Alert feat, giving us +5 to initiative rolls.

Rogue (Assassin) 3 gives us access to Assassinate, which guarantees a critical hit on a surprised enemy which has not taken their turn yet. (And Expertise in Stealth to guarantee surprise)

Monk (Four Elements) 3 gives us d4s for unarmed strikes, and Fangs of the Fire Snake, another 1d10 damage. Also the ability to use Dexerity for our unarmed damage rolls.

Items

Insignia of Claws gives +1 to the damage of Unarmed Strikes.

Enough Manuals of Quickness of Action to get this character to 30 Dexterity.

Damage (no helper)

So let's see how much we can do without our helper.

First we stealth up to our target and surprise them with our +22 to Stealth from expertise alone. Having remained undetected, we jump out. They are surprised. We roll initiative. We have +15 to initiative rolls, so should hopefully be able to beat them. Assuming we do, our attacks against them will be criticals. We cast Wrathful Smite with a bonus action, walk up to them, and hit them with our fist, burning a 4th level spell slot for a Divine Smite, and 2 Ki points to deal +1d10 damage with Fangs of the Fire Snake.

10 {Dexterity} + 1 {Insignia of Claws} + (1d4 {Monk unarmed die} + 5d8 {4th level Divine Smite} + 1d6 {Wrathful Smite} + 1d10 {Fangs of the Fire Snake}) * 2 {Critical hit from Assassinate}

= 79 damage

Helper

Our helper is a Cleric (Grave Domain) 2. They use their Channel Divinity: Path to the Grave feature to give this creature vulnerability to all the damage of the assailant's next attack. This doubles the damage above.