Paladin + Multi-Attack + Smite = Overpowered?

Question

In the AL game that I run a player's paladin rocks the polearm master paladin. He has been able to triple smite every big boss that I've thrown at him so far leaving me feeling a sense similar to an anti-climax.

I started to compare the paladin's damage spike to other classes at similar levels and feel that it may be an oversight. I suspect that a paladin should only be able to smite once per round, similar to Sneak Attack and spell casting.

Can someone explain how the paladin's triple smite stack vs other classes? Should I house rule this?

Answer 1

I would not houserule it

Smite is a finite resource, you have to spend a spell slot for it. So it is balanced very differently than Sneak Attack, but is still balanced.

If you want to give him more of a challenge, provide more enemies per day.

Calculation

For a triple Smite the Paladin is at least level 5, so the damage would look like this:

• 2x 1d10+Str+3d8 (spending all the 2nd level slots for the day)
• 1x 1d4+Str+2d8 (spending one 1st level slot)

The next round:

• 2x 1d10+Str+2d8 (spending two of the 1st level slots)
• 1x 1d4+Str+2d8 (spending the remaining 1st level slot)

In just 2 rounds he used up all his spells for the day, doing 4 times 6.3 damage (1d10 with Great Weapon Fighting style), 2 times 3 damage (1d4 with GWF), 3 for Strength (he took Polearm Master instead of a +2 Str), and alltoghether 14d8 from spells (63).
If every attack hits, it is 112.2 damage, or roughly 56 per round. It is indeed a lot, but by the third round, it drops to 25.6. And do not forget, he will not hit all the time, cannot use a shield, and his initiative is most likely bad.

He gave up quite a lot to shine once or twice a day

Answer 2

After looking it over, I assumed the character is level 5 and compared the maximum amount of damage that could be done and how often you can do it. Basically, as the rules are written, a level 5 paladin can do 2d10+6d8+d4+3xstrmod damage twice per long rest. The second time would actually be 2d10+8d8+d4+3xstrmod.(49+)

This amount of damage is much higher than the rogue or fighter or wizard damage in a tight burst. (8d6 for the wizard). However, the DMG suggests that a single target level 3 spell can do about 5d10 damage. (27.5) Which could, in theory, be twinned by a sorcerer to do 10d10 (55), but no such spell is currently available to the sorcerer to do that with.

This is limited to two times per long rest. During all other attacks, the Paladin would be doing 2d10+d4+3xstrmod.

I don't think it's appropriate to house rule an AL game, but this is certainly a larger level 5 nova than any other. And I'm rather surprised the errata didn't w clarify for smite to only be viable once per turn/round. While the nova is greater than any other available at level 5, it seems to me that it is within the damage limit of would be allowed with the highest damage spells.(If such spells existed). It should be noted that skills are balanced over the course of a day, with 6-8 encounters, not just single hits.

This has been confirmed by Jeremy Crawford.