I was in DM'ing a game the other day when the party's Level 3 Paladin one-hit KO'd a minor boss.

Here's how he did it:

Total damage = two-handed longsword (1d10) + Str modifier (+2) + Dueling fighting style (+2) + Divine Smite (2d8) + Sacred Weapon option from the Oath of Devotion (+5 from Charisma).

Using RAW, is this legal?

I allowed it to happen in our game because it was a great storytelling moment, but I just wanted to make sure if any rules were being broken. I read through the rules after the fact and I couldn't find anything that would stop this from happening. Am I missing something?

Sidenote: Yes, the PC is only level 3 and already has a +5 Charisma modifier. He just got really lucky when rolling out his stats.

There are a few problems here

First: you can't attack with two-handed weapons and get the dueling bonus
Does Dueling Preclude Use of Two-Handed Weapons? - check here if you have doubts.

Second:

Sacred Weapon: As an action, you can imbue one weapon that you are holding with positive energy, using your Channel Divinity. For 1 minute, you add your Charisma modifier to Attack rolls made with that weapon

This bonus is added to the attack roll, not to the damage roll. I.e., it increases your chance to hit, not your damage.

Also, note that it takes one action to get the buff, thus he can't attack in the same turn he used this feature.

Therefore, the actual damage on hit would be either

• 1d10 + 2 + 2d8 using the versatile property of the longsword


• or 1d8 + 2 + 2 + 2d8 attacking with only one hand of the longsword.