What is the most damaging one handed melee weapon?

Question

I'm looking for the most damaging weapon (meaning does the most damage to HP on a successful hit) that can be wielded in one hand. I am looking for an answer for both magical and mundane weapons. The only stipulations I have are that it must lack the two-handed property and must be found in one of the sourcebooks on D&D Beyond that isn't listed as an adventure. The ability modifier doesn't matter because I will be overriding that with my CHA mod anyway.

For mundane weapons the best I've found is a rapier or other weapon with equivalent damage (1d8) but I'm not sure if there's another, more damaging one. Also, the lance does not count because the only way to wield it one handed is to be mounted.

My intent is to have a character (hexblade warlock X / two weapon fighter 2) wielding the weapons. The mundane weapon is for the levels before I can easily get magic items and so I can conjure at least one to be my pact weapon for Pact of the Blade.

Answer 1

For mundane weapons, you have already found the answer.

• @Eternallord66 points out that warhammers would be a "best" choice, or flails; there are 12 monsters vulnerable to bludgeoning damage, 0 vulnerable to slashing damage, and 0 vulnerable to mundane piercing damage.

For magical weapons: a moonblade that has multiple runes on it and a Rod of Lordly Might.

Since the history and runic additions for a given moonblade are completely at the mercy of the DM who has that weapon in their world, two +3 warhammers/longswords/rapiers/battlezses would seem to be a more "practical" max since attunement to the weapons is not required.

But, if you have access to magical items that are "legendary" in your campaign ...

A more "practical" answer: a Rod of Lordly Might and a +3 weapon

If you push button two, you'd get two +3 weapons.
If you push botton one, you'd get a flame tongues which each do 2d6 additional damage, and your +3 weapon. The flame tongue adds seven damage on average unless the target is fire immune/resistant.

The above does not rely on the "how many previous owners" problem that the moonblade answer does.

Could you use a Flame Tongue and a Rod of Lordly Might together?

Technically yes. You can push button two to get a second flame tongue from the Rod, and end up with two flame tongues. Even though you are attuned to what looks like two flame tongues, you are actually attuned to a flame tongue and a rod of Lordly Might.

If you can find them, you want a Rod of Lordly Might and a Flame Tongue

(Longsword or rapier for the flame tongue so that it's one handed)

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Thanks to @V2Blast for reminding me that you can't attune to two copies of the same weapon

Answer 2

The other answers are pretty good if you want stability.

But what about a non-healable, potentially infinite (with enough luck & time), amount of damage ?

I have nothing against stability but I prefer my magic "Wild" and my dices rolling. So what about a Longsword of Wounding ?

• Swords of Wounding can be any type of sword so you can just choose a "non-Two-handed sword", like a Longsword of Wounding.

• The Damage Over Time (DOT) applied can technically do an infinite amount of damage per hit if the target never succeed either their saving throw or their Medicine check (which will consume an enemy action).

  • The DOT damage being Necrotic can be problematic if you know you'll fight mainly undead (most of them are at least resistant to it).

  • At the beginning of the target turn, it takes damages then do the save, guaranteeing at least 1d4 additional damage for each hit.

  • Even if succeed, the save/Medicine check doesn't grant immunity against this effect so you would just reapply it on your next hit.

  • The DOT stack each time you first hit in the turn (Attack of Opportunity out of your turn would apply it too), increasing the damages the creature takes at the start of each of its turn by 1d4.

• Since damage seems important, the fact that hit points lost to this weapon's damage can't be regained except by short or long rest sounds like a good auxiliary effect.

Answer 3

For Mundane Items the Flail and Warhammer are the most damaging because they both deal 1d8 bludgeoning. I say these weapons over the other 1d8 weapons based on the fact that in the MM there are four creatures vulnerable to bludgeoning and 8 others from the other books (as noted by Medix2). The other mundane damage types do not have this trait.

As @KorvinStarmast said, the Rod of Lordly Might, Flametongue and +3 weapons deal more damage on average than the others.

Overall the weapon that can do the most damage would be the Flametongue Rapier (as the war pick and Morningstar are not eligible by RAW for this magic weapon). It is magical piercing damage that also adds 2d6 Fire damage. This is only the most damaging based on the Rakshasa being vulnerable to magical piercing from good creatures and not having resistance or immunity to fire.