D&D 5E TWF and Extra Attacks as Bonus Action (help!)

[Laurefindel]

Let’s say that I want to have the extra attack granted by TWF stack with the extra attack granted by berserker barbarian, haste spell, and the « cleave » clause of GWM. Still, i want all of those to require a bonus action when use individually.

How should I word that out?

 

[TwoSix]

When you use a bonus action to make an attack granted by two-weapon fighting, you may use one additional bonus action, but only if the additional bonus action is used by a feature that grants a single melee weapon attack.

Basically, you have to write it as a lot of exceptions and specific call out to the type of ability you want, as bonus actions don't have any sort of keyword framework to leverage.

 

[Krachek]

All these feature give one extra attack. So they will stack over.
cleave usable once per turn.

 

[DND_Reborn]

If I am understanding you correctly, maybe something like this:

When you take the attack action on your turn and make a weapon attack, you can combine any features you can use that require your bonus action into one bonus action.

Note: Haste provides an additional action, not a bonus action. That action can be used to attack, but only for one attack.

 

[NotAYakk]

Two Weapon Fighting: You are considered to be two weapon fighting when wielding a light melee weapon in each hand. While two weapon fighting, on your turn you may do one of the following:

• If you make a melee weapon attack as a bonus action, you may also make a melee weapon attack with the weapon in your other hand.
• If you make a melee weapon attack as part of the attack action, you may make a melee weapon attack with the weapon in your other hand as a bonus action.

but not both. Attacks granted by this rule do not add your attribute to damage.

Design Notes:
I attempt not to be clever.

It does not stack with monk extra attacks, as it requires using a weapon in your hand, unless you have a weapon that somehow counts as an unarmed attack as well.

Quickened booming blade (etc) will trigger the bonus action clause, but not the main clause because the attack isn't part of the attack action, but rather a spell. You could reword that if you want, but then twf stacks with multiattack (for example) as well.

It is specific to TWF, not general. I consider that a plus.

It does nothing different with haste: if you want haste to give you an extra offhand attack, I don't agree nor do I know clean wording. Haste already "stacks" in that the extra haste attack is not a bonus action.

It does stack with the scimitar of speed. A +3 Scimitar and a +2 Speed on a level 20 Fighter gets 6 attacks (5 with +3 one with +2, snd one of the +3s does not get str-to-damage).