[Note that my tongue is in my cheek, where admittedly I am biting on it out of frustration, i.e. I am being facetious, but with serious intent. In other words, don't take it personally!]
Hi, I am the DM that kewlpack is referring to. Let me please explain my rationale, because I want clarification, preferably from a Pathfinder developer (if it is not too much trouble to assist the paying customer). The rule system is complicated and at times contradictory, as this example shows. I don’t like a rule system that requires assumed knowledge and cross-referential analysis to understand.
The key sentence here is "When you use the attack action, you can make one attack at your highest base attack bonus that deals additional damage.” This is a matter of determining the meaning of “attack action”, and properly parsing the sentence.
An ‘attack’ can be a standard action, part of an attack in a standard action that can result in subsequent attacks, or part of a full-attack in a full-round action (there may be more, but this starts to illustrate my point). The term ‘full-attack action’ is quite clear, but the term ‘attack action’ is used in a variety of ways:
1) See the Core Rulebook, page 124 for an example of the phrase ‘attack action’ being used in a feat, “Great Cleave”, that involves multiple attacks during a standard action.
2) See the reference to ‘the attack action’ on page 178, which refers to page 182 where the exact term ‘attack action’ is not defined. This seems to imply that an ‘attack action’ is a ‘Standard Action’, but does not exclude it from being part of a full-attack or other multiple attacks.
3) See Sunder on page 201 for an example of an ‘attack action’ being something in place of a melee attack, implying it is not strictly a Standard Action, but this then depends on the meaning of ‘melee attack’, which is used profusely and inconsistently though never defined. The closest is footnote 6 on page 183: "Some combat maneuvers substitute for a melee attack, not an action. As melee attacks, they can be used once in an attack or charge action, one or more times in a full-attack action, or even as an attack of opportunity. Others are used as a separate action.” This supports my interpretation.
I took it to mean ‘an attack’, which can be done as part of a standard action or a full-round action, i.e. as one of many attacks.
Next comes the sentence parsing. The clause "you can make one attack at your highest base attack bonus that deals additional damage.” could be parsed to have two different meanings:
1) "you can make one attack, at your highest base attack bonus that deals additional damage” meaning you literally can make only one attack, it is at your highest attack bonus, and it deals additional damage.
2) "you can make one attack, at your highest base attack bonus, that deals additional damage” meaning that you can make only one attack (one that is at your highest bonus) that deals this additional damage, and any other attacks do not.
The Vital Strike series of feats are the only ones that use this exact phrasing, whereas others explicitly use the phrases “a single attack” or “a full-attack action” to distinguish between one-and-only-one attack or something that is part of a full-round action that could include multiple attacks. So I assumed that there was a reason for this, and that it was to be interpreted according to the second parsing, because the missing specific phrases would have been more consistent with the first parsing.
I realize that I have ignored the phrase ‘single attack’ in the descriptive text of the Vital Strike feats. This is because the descriptive text tends to have generalized and sometimes conflicting statements, so I defer to the specified subsections of the feat format as stated on page 113, where the descriptive text is not technically part of the feat definition. To use information in the descriptive text to decide what the rule means would be like using something in the abstract of a specification (RFC) to determine how to implement the specification (this is what I do for a living for 20+ years, analyze protocol and software specs to determine how they are to be implemented.) The abstract is just a descriptive introduction and has no further purpose in defining the spec, as is the descriptive text at the beginning of a feat.
However, since that phrase is there, I will grant Kewlpack the right to restrict his Barbarian as he wishes. God help him if that barbarian gets a chance to refute him face-to-face.
Yet, there is one last issue here! How do you know for what the Vital Strike feat is meant when this asserted intention is not in the text? This is assumed knowledge (supposedly said by the developers). The FAQ being referenced herein says nothing of the sort. Furthermore, there are several precedents that contradict what the FAQ states: See page 109 of the NPC codex, the Grove Guardian Half-Elf Monk, which states "Against foes too large to grapple or immune to stunning, she uses her ki pool to boost her movement, then Spring Attack with Improved Vital Strike to make hit and run attacks." (Find a similar examples on Page 206 and 218.) There is another example on Page 124, the Axe Lord Dwarf Paladin, who "uses Improved Vital Strike and Cleave if he has a few targets close together", which goes against what Quintain said, that Vital Strike cannot be combined with other standard actions such as Cleave. In other words, there is plenty of official precedence showing that Vital Strike can be combined with both standard actions and full-round actions, and therefore is not exclusively for occasions where the martial character only gets a single (one-and-only-one) attack. If it can be combined with other full-round actions, then why not with a full-attack action?
So, now for the real reason that I posting such an in depth analysis:
If it is not too much bother, I humbly ask that someone who can act officially for Pathfinder to kindly address the discrepancies and inconsistencies in the rule system. Either fix them, or at least reply to some of these disdainful threads.
By the way. two weapon fighting is another vexing, convoluted rule. It requires one to locate the correct phrase under the Full-Attack action of the Combat chapter, page 187. There is no reference to this critical information within the Two-Weapon Fighting feats, or the Two-Weapon Fighting special attack to which they reference. It is unfortunate that the players don’t all read and memorize the core rulebook cover-to-cover, but it does happen. This has resulted in much abuse and arguing over what a two weapon fighter can do in a round. It could be fixed simply by putting the phrase, “when making a full-attack action”, in the feat and/or special attack definitions.
