I've been thinking about the two-weapon fighting rules a bit. They're simple and they work, but they have a couple of minor balance issues. Nothing you haven't heard before: using a bonus action to get an extra attack is good at lower levels, but is overshadowed by the raw damage of a two-handed weapon once the warrior classes start getting extra attacks. Plus you have to use your bonus action, which makes rogues and berserkers sad.
So here's an alternative for discussion:
- When make an attack, whether it's a main attack, extra attack, opportunity attack, or anything else, if you're wielding two weapons, you can make an attack roll with each weapon. However, only the attack with the higher roll can hit or deal damage -- the other one was a feint.
- As normal, if you hit with your off-hand weapon, don't add your ability modifier to damage unless you have the Two-Weapon Fighting combat style.
- When you have advantage, since two-weapon fighting already resembles advantage, don't roll any more dice. Instead, both attacks are allowed to hit. When you have disadvantage, only the lower attack roll is allowed to hit.
It frees up the bonus action, it scales with extra attacks, and I think it gives two-weapon fighting a more defined niche: draw a heavy weapon when you want massive damage, but draw two light weapons when you want
reliable damage.
I think it's a bit much. With advantage, a dedicated TWF fighter (with both fighting style and feat) is potentially dealing 2d8+10 damage (before magical bonuses) on every attack. That kind of damage will be difficult for even a GWF fighter to match. If you throw an additional 2d6 damage on each attack from Hunter's Mark or the like, the GWF gets left far behind.
Admittedly, that's the idealized scenario of always having advantage, and hitting with both attacks, which certainly isn't going to always be the case. Nonetheless, I don't think TWF should be allowed to be that far ahead of GWF in any scenario, given that the TWF feat also bolsters your defense, and that it's not bad under normal or DA circumstances either.
I also don't like that it requires you to track which d20 is associated with which attack. It's too fiddly for my tastes and I've known players who (intentionally or otherwise) would mix up which die belonged to which attack (back in the days of iterative attacks). I've found that sort of mechanic to be both slow and error-prone in the past.
As for sad rogues, you shouldn't be able to eat your cake and have it too (I say this as someone who is currently playing an Arcane Trickster). Having a second chance to land sneak attack is well worth having to give up cunning action for that round. It should be a tough choice; you don't get to retry for sneak attack
and also skirmish in the same round. Except for Swashbucklers, but that's their schtick which has its own limitations. I have more sympathy for berserkers, but the barbarian is simply not designed for TWF. It's like playing a low intelligence wizard; you can do it, but it's mechanically disadvantageous plain and simple. IMO, if you want dual wielding barbarians you should either add a class feature which makes it beneficial for them to do so (like the TW fighting style) or build a new barbarian path that centers around using two weapons.
If I were going to do this, here's how I might implement it:
- When you make an attack, whether it's a main attack, extra attack, opportunity attack, or anything else, if you're wielding two weapons, you can roll an extra d20 and take the better roll. If the unmodified roll is even, the attack is made with your primary hand, while if it is odd it is your off-hand. If you roll matching numbers (doubles) the attack is made with both hands.
- As normal, if you hit with your off-hand weapon, don't add your ability modifier to damage unless you have the Two-Weapon Fighting combat style.
- When you have advantage, roll 3 d20s and take the two highest. When you have disadvantage, roll 3 d20s and drop the highest roll.
I haven't done much mathematical analysis on this to see if it's balanced, but here's the breakdown. Having 3 dice might seem like a large amount, but whereas normal advantage is roughly the equivalent of a +4, having three d20s only adds about the equivalent of +2 on top of that. 2d20 gives you a 9.75% chance to crit, whereas 3d20 gives you a 14.26% chance. However, regardless of whether you have advantage, disadvantage, or whatever, your chance for a double attack is always fixed at 5%. That's important because, as I showed above, a double attack can pretty easily beat even GWF attacks.
My proposal makes TWF very reliable while reining in the probability of massive damage. Like your idea, under normal circumstances both houserules effectively grant advantage. Under your system however, advantage becomes a gateway to massive damage, whereas under my system it mostly just increases accuracy (with a small boost to damage from the increased chance to crit). Under your system, disadvantage is basically standard (no benefit from TWF), while my system makes disadvantage effectively a normal attack from a non-TWFing fighter (and therefore again more reliable).
I don't know whether my idea is reasonable or not (that would require more consideration and analysis to see how it stacks up against GWF and how it could be abused) but that's where I'd start if I were to go this route.
When fighting with a weapon in each hand, roll both damage dice together on a successful hit, adding your relevant modifier once as normal.
The problem with this is that if you have the TWF feat, you're dealing 2d8+modifier damage, which seems excessive. Also, it makes the fighting style irrelevant.
I moved the extra attack from a bonus action to just being part of the attack action if you have the feat or the fighting style. This lets rangers dual wield and cast at the same time, and fighters effectively get 2 offhand attacks when they action surge. Simple and non-fiddly. The rest I can fix by throwing the TWF guy an extra +1 on his magic weapons or whatever over the GWF guy.
I will be stealing this for my campaign.
Although I think I'll leave it off the feat. I don't want rogues to be able to dual wield without having to sacrifice a bonus action, at least not without having to dip at least a warrior level (which slows their SA progression).
