Can I use Two Weapon fighting with Heavy weapons by being enlarged?

Question

I love the idea of two-weapon fighting, and tinkering around with it. My character is going to be a Paladin. But to effectively dual wield as a Paladin I need to delve into either Ranger or Fighter, unless the DM is gracious and gives me Two-Weapon Fighting Style instead of the Paladin's normal choices. For the purposes of this question, we will assume that isn't the case.

Paladin 12 / Fighter 8 is the final build. Only going up to 12 in Paladin for the automatic divine weapon smite 1d8 bonus on damage attacks and the ASI. I'll be doing Vengeance for Hunter's Mark, adding another 1d6 per attack. Assuming Dual Wielder Feat, an attack should be roughly 2d8 + 1d6 + mod, which is relatively decent in my eyes considering you do that 3 times per round + occasional smiting on critical hits.

For Fighter at level 3 I would be going Eldritch Knight for bonding weapons and more spell slots.

This is where things can get a bit fun, and a bit iffy. From what I have read, wielding a heavy weapon in one hand gives disadvantage on attack rolls. Using the 2nd level spell Enlarge, you then pull out two bad ass heavy weapons and proceed to two-weapon style with them.

Honestly this is completely up to DM ruling and whatnot. For example PHB p. 147:

Two-Handed. This weapon requires two hands when you attack with it.

Based on that alone you could overrule having a greatsword in each hand, even when under the effects of enlarge. Becoming a size category larger would make sense that you could wield heavier weapons though, for the same reasoning small creatures can't use heavy weapons all that great but medium can. Enlarge only lasts for 1 minute, and requires concentration, so if you fail a concentration saving throw to maintain it you are now stuck with two huge weapons you can't really use, forcing you to switch back to regular ones.

Another question would be does the added 1d4 damage apply to the greatswords.

The target’s weapons also grow to match its new size. While these weapons are enlarged, the target’s attack with them deal 1d4 extra damage.

Would switching to the greatswords beforehand add in the extra damage? Or would they now be even bigger and your new size unable to wield them anyway? I could always switch to the greatswords after the spell has been cast. In either case, could this work?

Answer 1

could this work?

No. All weapons with the "heavy" property have the two-handed property as well. Here's exactly what each property does (PHB 147):

Heavy. Small creatures have disadvantage on attack rolls with heavy weapons. A heavy weapon's size and bulk make it too large for a Small creature to use effectively.

Two-Handed. This weapon requires two hands when you attack with it.

The heavy property itself isn't a problem here, but the two-handed is. Since all heavy weapons are also two-handed, you must use two hands to wield them. The enlarge spell doesn't give you the ability to wield a two-handed weapon in one hand, even if that weapon wasn't enlarged with you. Your DM might allow it, but it's certainly not part of the Rules As Written.

So what can you dual wield, then? Here's the rules on two-weapon fighting (PHB 195):

When you take the Attack action and attack with a light melee weapon that you're holding in one hand, you can use a bonus action to attack with a different light melee weapon that you're holding in one hand. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

Based on this, you can only dual wield light melee weapons. You don't even need the two-weapon fighting style, since all the fighting style does is allow you to add your ability modifier to the bonus action attack. There is a way to get around the "light" limitation, namely the Dual Wielder feat (PHB 165, emphasis mine):

You master fighting with two weapons, gaining the following benefits:

• You gain a +1 bonus to AC while you are wielding a separate melee weapon in each hand
• You can use two-weapon fighting even when the one-handed melee weapons aren't light
• You can draw or stow two one-handed weapons when you would normally only be able to draw or stow only one.

This feat allows you (among other things) to use any one-handed melee weapons for two-weapon fighting.

In conclusion, you're not going to be two-weapon fighting using greatswords, even if you're enlarged. The closest you're going to get would be two longswords with the Dual Wielder feat

Side note: If you want to do two-weapon fighting purely from an optimisation perspective, you may want to reconsider. It is generally accepted as one of the weaker playstyles, as it uses your bonus action to be effective (needed to cast smite spells on a paladin, for example), and still can't quite compete with great weapon fighting, especially if you factor in the Great Weapon Master feat. It doesn't fall completely behind other playstyles, so if you want to do it because of a character concept, go ahead. But if it's exclusively for optimisation, it might be better to just use a single greatsword.

Answer 2

You could modify the weapon system to account for weapon size and character size.

Weapons are tiny, small, medium, or large.

You need one hand to wield a weapon (Your size) and smaller and two hands for one (Your Size + 1). You cannot use weapons (Your size + 2) and larger.

To wield two weapons at once, both must be (Your size - 1) or smaller. If you have the Dual Wielder feat then both must be (Your size) or smaller.

For example, a Gnome (a small creature) could dual wield two daggers (tiny weapons) but not two shortswords (small weapons). She could use a longsword (medium weapon), in two-hands, but she could not use a glaive (large weapon).

Answer 3

i might have found way to dual wield while using a great sword. Yes the great sword needs 2 hands to attack but NOT to hold. so if you lets say had a hand ax in one hand and then a great sword in the other you could start off with an off-hand attack of throwing the ax then you'd have both hands to use the great sword. I'm pretty sure this would work.