Are there any balance problems or unintended consequences of allowing a PC to use natural weapons for two-weapon fighting?

Question

I’ll preface this by stating that I do realise that by RAW natural weapons are not compatible with two-weapon fighting.

However, would it significantly unbalance things or break anything to allow it? The PC in question is a Barbarian of Path of the Beast and they get a bunch of natural weapons options at level 3, specifically they want to use their claws for it:

Claws. Each of your hands transforms into a claw, which you can use as a weapon if it’s empty. It deals 1d6 slashing damage on a hit. Once on each of your turns when you attack with a claw using the Attack action, you can make one additional claw attack as part of the same action.

The 1d6 damage that the claws deal is on par with handaxes, scimitars and shortswords, all of which qualify for two-weapon fighting so I don’t think allowing it is going to make the PC dramatically more powerful, after all they could just grab a pair of handaxes and have the exactly same damage output. I do realise that with the claws they’ll get one extra attack as part of their Action, which they would not get with weapons and I’m ok giving it to them.

Also the PC is level 5 already and have the Extra Attack feature so technically they could just attack with their claws first to get the additional attack and then switch to the axe to still qualify for the off hand bonus attack.

Is there anything that I’m missing or forgetting about this that could cause problems down the line?

Answer 1

You are not missing anything

A second attack with your claws is already baked into the Claws feature, it just does not cost you a bonus action as two-weapon fighting would. The most natural way to think of this is that you attack with both claws, but technically, you do not:

Once on each of your turns when you attack with a claw using the Attack action, you can make one additional claw attack as part of the same action.

This does not require you to have two free hands/claws, and could be done with a single free claw (for example, if you hold a shield in the other).

Two-weapon fighting normally (without feats) requires light melee weapons in both hands. All of those in the core rules do d6 or less damage. That means, there will be no improvment for the off-hand claw attack, and no improvement for the first main-hand claw attack, but as you say, you get another main hand claw attack for free compared to normal two-weapon fighting from the extra claw attack of Claws.

This certainly is a tangible power-up compared to the rules as written, but at at +3.65 damage before to hit chance per round it won't break the game in a way that is significantly unbalancing.

Especially not as you have access to extra attack and feats already. Two-weapon fighting is generally seen as one of the weaker melee combat options that at higher levels loses steam compared to polearms or great weapon fighting with the appropriate feats, even when you have the Dual Wielder feat. And here you cannot use that effectively as it allows you to use larger weapons, and you don't use weapons. So the homebrew rule would help to offset a weaker option to make it compare better and be more attractive.

The only possible risk I can think of would be with features that pay off on a critical hit (for example, if the Barbarian also would take Paladin levels for Divine Smite), as more attacks means more chances to land that hit. But I do not think that this would be more abusive than other optimized builds, if at all.

Answer 2

Unlikely for a barbarian, but spellcasting becomes less of an issue

By allowing natural weapons for two-weapon fighting, you are allowing a creature to 'wield' two weapons without anything in their actual hands. This will free up a hand for spellcasting where normally you wouldn't have one (sword and board or two-weapon takes up both hands.)

This is clearly not a huge issue for a barbarian, but a dip for spellcasting would be a nice addition (maybe not in combat because rage), but an eldritch knight or any other caster-melee combo would gain a boost here to bypass the issues of hands holding things and not being able to cast S or M component spells.