How does the Multi-Weapon Fighting feat 'replace' the Two-Weapon Fighting feat?

Question

The Multiweapon Fighting feat clearly states that it Replaces two-weapon fighting for creatures with more than two arms. What does that mean?

I've given it some thought, and I can think of only three real possibilities.

1.) For all instances where 'two-weapon fighting' is mentioned, any creature with more than two arms replaces it within the rules with 'multiweapon fighting.' So, all feats, abilities, rules, etc., associated with two weapon fighting apply to multiweapon fighting as though it were the same feat, with any mention of a 'off-hand' referring to All off hand weapons, equally.

2.) The feat simply replaces the two-weapon fighting feat, and thus creatures with more than 2 arms just can't take two-weapon fighting and must instead take multiweapon fighting. By extension, they can not benefit from any of the other two-weapon feats, because they all have two-weapon fighting as a prerequisite, which can not be taken by a creature with more than two arms.

3.) The feat replaces two-weapon fighting as it does in example one, with the exception that all abilities, feats, etc. referring to an 'off-hand' apply to only one off hand, either per turn or in general.

Answer 1

The first option

In my opinion, the first option is the most likely interpretation of the rules as written, probably what the authors were going for, and the best way to run things at the table.

Multiweapon Fighting does exactly the same thing as Two-Weapon Fighting, it just affects more weapons. So if you have more than two weapons, you use Multiweapon Fighting instead of Two-Weapon Fighting, but they amount to the exact same thing.

The game works better if you basically pretend they’re the exact same feat; the distinction is only made because Two is such a common default, and Multi is usually reserved for more monstrous creatures (though there are plenty of ways to access it as a PC).

Answer 2

It's the first option. The rules for Multiweapon Fighting make it clear that one hand is the primary hand and all the others are off hands with the following statement.

(It has one primary hand, and all the others are off hands.)

Any other place in the rules that an off hand is mentioned, for example, in the following excerpt from the Two Weapon Fighting rules (that Multiweapon Fighting references), the rules for the off hand apply to all the off hands you have.

If you wield a second weapon in your off hand, you can get one extra attack per round with that weapon. When fighting in this way you suffer a –6 penalty with your regular attack or attacks with your primary hand and a –10 penalty to the attack with your off hand. If your off-hand weapon is light, the penalties are reduced by 2 each.

As the above quote is written for the Two Weapon Fighting feat description it only mentions a singular off hand but the Multiweapon Fighting feat description makes it clear, by saying all other hands are off hands and by specifically referencing the Two Weapon Fighting rules, that you can have multiple off hands if you have enough arms.

Answer 3

2.) The feat simply replaces the two-weapon fighting feat, and thus creatures with more than 2 arms just can't take two-weapon fighting and must instead take multiweapon fighting. By extension, they can not benefit from any of the other two-weapon feats, because they all have two-weapon fighting as a prerequisite, which can not be taken by a creature with more than two arms.

This option seems correct if you look strictly at the rulebooks.

For creatures with more than two hands, it is required to take Multiweapon Fighting instead of Two-Handed Fighting. By extension, Improved Multiweapon Fighting replaces Improved Two-Weapon Fighting, Greater Multiweapon Fighting replaces Greater Two-Weapon fighting, And Multidexterity replaces Ambidexterity.

The Two-Weapon and Multiweapon feat trees are separate. Feats that have Two-Weapon Fighting as a prerequisite, such as Two-Weapon Defense, clearly speak about Double Weapon or Two-Weapon fighting, and no Multiweapon equivalents exist of these feats. As a result, these feats are unattainable for creatures with three arms, unless house rules specify otherwise.

The Epic Level Handbook states in the Greater Multiweapon Fighting feat (p.69):

This feat replaces the Greater Two-Weapon Fighting feat for creatures with more than two arms (and functions identically to that feat if you have fewer than three arms).

Whether functioning identically means that it is regarded as the same feat, and can thus be used to replace the Two-Weapon fighting prerequisite, is unclear.

Improved Multiweapon Fighting and Greater Multiweapon Fighting also appear in Savage Species and Deities and Demigods rulebooks. The articles on Two-Handed Fighting mechanics by Skip Williams make no mention about creatures that have more than two arms. With a lack of elaboration, I feel the second option is the correct one.

Answer 4

By RAW, I believe option 2 is the current correct answer. If a creature has 3 or more arms, it cannot take the Two Weapon Fighting Feat, and can only take the Multiweapon Fighting Feat. No other feats use Multiweapon Fighting as a prerequisite, meaning most of the standard Two Weapon Fighting options are not at all available to creatures with 3 or more arms.

I suspect option 1 was what the authors intended, but it doesn't read that way, and opens up a bunch of worm-cans, since the subsequent feats are all written to assume a single off-hand. For instance, if Multiweapon fighting allows you to qualify for Two Weapon Defence, do you get additional defence benefits for the 3rd and 4th arms? How does Two Weapon Rend work with more than two arms - do you have to hit with at least one off-hand, or all of your off-hands?

Answer 5

There is a solution(of sorts) that involves going back to 3.5 rules(from which Pathfinder evolved). They can be found in Here under the section on Non-Epic General Feats.

Improved Multiweapon Fighting [General]
Prerequisites: Dex 15, three or more arms, Multiweapon Fighting, base attack bonus +9.
Benefit: In addition to the single extra attack a creature gets with each extra weapon from Multiweapon Fighting, it gets a second attack with each extra weapon, albeit at a -5 penalty.
Normal: With only Multiweapon Fighting, a creater can only get a single attack with each extra weapon. Special: This feat replaces the Improved Two-Weapon Fighting feat for creatures with more than two arms.

As well as:

Greater Multiweapon Fighting [General]
Prerequisites: Dex 19, three or more arms, Improved Multiweapon Fighting, Multiweapon Fighting, base attack bonus +15.
Benefit: The creature may make up to three extra attacks with each extra offhand weapon it wields, albeit at a -10 penalty on the third attack with each weapon.
Special: This feat replaces the Greater Two-Weapon Fighting feat for creatures with more than two arms.

Due to this, it would follow logically that for feats such as Two weapon defence, MWF replaces all instance of TWF in the description. The closest comparison I can think of is for archetypes that modify certain abilities such as the modification done to Throw Anything for the alchemist.

On further research however, I have found that Paizo has released a version of Multiweapon Defence(Found) which would incline me to believe that there are in fact no Pathfinder only ways of gaining access to the TWF chain for creatures that are fighting with 3 or more arms.

If however you wish to include a MWF progression to replace/complement TWF, it can be found here, but does require going back to 3.5 material.