Does a fighter's Action Surge allow 2 off-hand attacks as bonus actions? [duplicate]

Question

A fighter at lvl 20 with dual wielding and two weapon fighting should effectively make up to 10 attacks in one turn using action surge.

Two weapon wielding states you may make a bonus action when you take an attack action and having dual wielding you may use any weapon. Therefore there are four attacks, a bonus because you attacked, then Action Surge also gives four attacks, and one more bonus because you attacked.

I understand PHB says you may only take one bonus action but it also says you may only take one action. Action surge clearly violates this so I believe it would also grant another bonus action since two weapon fighting clearly states per attack action and not turn. Especially since you don’t have to use action surge to attack anyways. Can anyone clarify this?

Answer 1

Action surge does give you an extra action, but it does not give you an extra bonus action. "On your turn, you can take one additional action on top of your regular action and a possible bonus action." p.72, PHB.

Answer 2

You have exactly 1 bonus action per turn even if you have multiple abilities granting you a bonus action. The exact rule found on the PHB p.189 is:

You can take a bonus action only when a special ability, spell, or other feature of the game states that you can do something as a bonus action. You otherwise don’t have a bonus action to take. You can take only one bonus action on your turn, so you must choose which bonus action to use when you have more than one available. (emphasis mine)

To clarify, think of it as having a list of bonus action options on your turn:

1. Make an attack with a different weapon (if you meet the requirements for two weapon fighting)
2. Second wind
3. Some other feature that grants a bonus action

If at any time during your turn you use the attack action and meet the two weapon fighting requirements you are enabling option 1. Even if we consider that using the attack action a second time means adding to the list:

4. Make an attack with a different weapon (if you meet the requirements for two weapon fighting)

You must still choose only one of these options.

The wording "a bonus action" is used in many features that grant you a bonus action while not explicitly overriding the rule of allowing only one bonus action per turn. To quote some examples (all emphasis mine):

Rage (PHB p.48)

In battle, you fight with primal ferocity. On your turn, you can enter a rage as a bonus action.

Bardic inspiration (PHB p.53):

You can inspire others through stirring words or music. To do so, you use a bonus action on your turn to choose one creature other than yourself within 60 feet of you who can hear you.

Second Wind (PHB p.72):

You have a limited well of stamina that you can draw on to protect yourself from harm. On your turn, you can use a bonus action to regain hit points equal to 1d 10 + your fighter level.

This is no different than the wording for two-weapon fighting (PHB p.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 the other hand.

Compare this to Action Surge which states (emphasis mine):

On your turn, you can take one additional action on top of your regular action and a possible bonus action.

This is explicilty overriding the rule that you have only 1 action per turn by using "additional" and "on top of".

Answer 3

You only get 1 bonus action per turn, giving you 9 attacks total.

Action surge gives you another action that turn. Two-Weapon fighting allows you to spend a bonus action on an extra attack when you take the attack action. If you take 2 attack actions you can spend your bonus action during either one of those attacks, but can't spend it on both because you only have 1 to spend.

Action Surge does change the general rule of "1 Action per turn", but it never says anything about bonus actions so it doesn't change the rule of "1 Bonus action per turn".

Answer 4

If action surge allows an extra action when normally you can only have one it should effect bonus as well considering the wording of two weapon fighting states you may take a bonus action when you take an attack action which is what action surge allows you to do.