What is the most damage that can be done in one round to a single target with spells?

Question

I'm new here, but I scrolled through and did not see this question answered. I would love to see your theory-craft at work!

What is the most damage you can do to a single opponent in one round, with spells of any class?

Rules:

• I play RAW, so if you are going to use any UA please have a separate category for it. No 3rd-party stuff, please.

• No setup round

• Damaged from anything summoned counts, as long as it attacks on your initiative

• No outside help; this is about you.

• Target is not restrained, or vulnerable, or resistant, unless you find a way to make him that way.

• No crits unless you have a way to guarantee them.

• Assume that you automatically hit, and that creatures fail saving throws.. but bonus points if you can give reasons why you have a better chance at it.

• The opponent is generic, so you can't tailor the spell to a specific monster for more damage.

• Use any feat, including dragonmarks to get an epic boon...

• Level max is 20 using any race, class, or combination of classes

• Use any magic item (as many as you like)

• Spells that include a weapon attack are allowed (like booming blade)

• Flame blade or spiritual weapon are also allowed

• This calculation is about what you can inflict on someone intentionally, so no reaction spells. However, damage that is done on the opponent's turn in the same round can be added like that from booming blade.

I can't wait to see what you guys come up with. I'll add my own as well!

Answer 1

With perfect rolls, arbitrarily much

We need a 1st level Wild Magic sorcerer with the Boon of Spell Mastery epic boon (DMG p. 232). We choose one of our sorcerer spells that deal damage on a spell attack for that boon, let's say chaos bolt.

Our loop is quite simple. We cast our chosen 1st level spell without expending a slot using Tides of Chaos to gain advantage. Our DM has us roll of the wild magic surge table to regain the use of Tides of Chaos. We roll a 81 or 82 which lets us take one additional action immediately. We use this action to cast the 1st level spell again with all the above events.

We can repeat this loop until our target is dead, the dragons fall out of the sky, or our playgroup gets up and leaves.

Answer 2

With spells only, 80d6, for an average of 280 or maximum of 480 damage.

With the Boon of High Magic, 2 levels of Fighter, 17 or more levels of Sorcerer or Wizard, and the spell Meteor Swarm.

Step 1: Cast Meteor Swarm on the target 40d6 damage.

Step 2: Use Action Surge (from your 2 levels of Fighter) to gain a second action.

Step 3: Cast Meteor Swarm again (via the Boon of High Magic) for another 40d6.

Unfortunately, you can't add an extra spell into the mix with the Sorcerer's Quickened Magic metamagic option, because casting a spell as a bonus action would restrict the spells cast as actions to cantrips only.

If you're willing to include a weapon attack to force spell effects to trigger, 101d6 + 11d8 + 7, for 410 average or 701 maximum damage (plus other non-damaging effects).

This is going to involve 3 levels of Fighter (Battlemaster), 17 levels of Wizard, 20 Strength or Dexterity, a Scimitar of Speed, the Boon of High Magic, the Pushing Attack battlemaster maneuver, and the spells Prismatic Wall and Thunderwave.

Step 1: Cast Prismatic Wall immediately behind your target (consuming your first 9th level spell slot).

Step 2: Use Action Surge to gain a 2nd action.

Step 3: Cast Thunderwave on your target at 9th level with the Boon of High Magic. They fail the save, taking 10d8 thunder damage and getting pushed back 10 feet through the Prismatic Wall.

Step 4: Watch your target make 7 Dexterity saving throws as they are pushed through the wall, taking 10d6 damage of various types for the first 5 layers of the wall, and possibly being petrified or banished on the last 2.

Step 5: If your target is still alive and non-banished, use your movement to walk through the wall and position yourself so that the target is between you and the Prismatic Wall again.

Step 6: Use your bonus action to make an attack with the Scimitar of Speed, dealing 1d6 + 7 damage.

Step 7: When the attack hits, add the Pushing Attack maneuver, dealing an additional 1d8 damage and pushing the target back through the Prismatic Wall (if they fail their save, which we're assuming they do).

Step 8: Watch the target go through another 7 Dex saves.

Note that this is predicated on forced movement activating the Prismatic Wall's effects, which is supported here, and the target must be Large or smaller for the Pushing Attack maneuver to effect it.

Answer 3

With the right spells and preparation, an average of 2139 damage

Classes: Lvl 17 Bladesinger Wizard, 1 Hexblade Warlock, 2 Fighter

Race: Half Elf

Feats: Gunner, Elven Accuracy, Eldritch Adept - Agonizing Blast

Fighting Style: Dueling

Items: Illusionist's Bracers, +3 Rapier, multiple uses of Tome of Clear Thought for a total of 30 INT, multiple uses of Tome of Leadership and Influence for 30 CHA. Items premade with the following on your character: a [Glyph of Warding] set to cast [Spirit Shroud] at 9th level when your turn starts, a [Glyph of Warding] set to cast [Haste] when your turn starts, a [Glyph of Warding] set to cast [Contagion - Flesh Rot] at the target (Vulnerability to all damage) when your turn starts, a [Glyph of Warding] set to cast [Hold Person] or [Hold Monster] at the target (Paralyze so always crit on attacks within 5 feet) when your turn starts.

The Turn:

Action: Attack with your melee attack for 2(2d8+15+8d8), replace 2nd attack with Eldritch Blast (Bladesinger) for 2(8d10+40+32d8)

Hasted Action: Single Attack, Replace attack with Eldritch Blast (Bladesinger) for 2(8d10+40+32d8)

Action Surge: Attack with your melee attack for 2(2d8+15+8d8), replace 2nd attack with Eldritch Blast (Bladesinger) for 2(8d10+40+32d8)

Bonus Action: (Illusionist Bracers) Eldritch Blast for 2(8d10+40+32d8)

Total Damage: Avg - 2139, Max - 3534

Honestly I could get higher if I wanted to further abuse glyphs of warding, but I think this is already FAR beyond ridiculous and covers the major offenders.

Answer 4

Goblin: Fury of the small +20 damage

Lv 17 wizard Evoker, Lv 2 Fighter, lv 1 Warlock Hexblade

Feat: elemental adept (goes through damage resistance)

Feat : dragon mark, epic Boon high magic (+one 9th lv spell slot)

Magic Item: ring of 3 wishes

Start of Turn

Round 1 Action: cast time stop

(Timestop Round) 0.1 Action: wish, glyph of warding set Scorching ray (2d6 x9) set to go off verbally (no action)

(Timestop Round) 0.2 Action: wish, glyph of warding set Scorching ray (2d6 x7) set to go off verbally (no action)

(Timestop Round) 0.3 Action: hold monster (breaks time stop) for x2 crit

Round 1 Bonus: Hex curse +6 x 24

Round 1 Surge: Scorching Ray Lv 7 slot. 2d6 x8

Round 1 Free action: Set off glyphs of warding verbally.

Overchannel : Spells do max damage

Fury of the small +20dmg

Evoker +5

Critical hit x2 on all rolled damage from hold spell.

745 Min 745 Max

745 Avg