Throwing a weapon as an improvised weapon

Question

In Pathfinder, if a weapon is thrown by a character at a target, does it become an improvised thrown weapon?

For example purposes, the character in question is a Barbarian with the feat Throw Anything, trying to throw a great club at a target.

Answer 1

(Very) strict RAW: No.

Rules-Lawyering this is actually kind of weird. Throwing a melee weapon (with no range increment) is covered in the Weapons section of the rules.

Thrown Weapons: [...] It is possible to throw a weapon that isn't designed to be thrown ([...]), and a character who does so takes a –4 penalty on the attack roll. Throwing a light or one-handed weapon is a standard action, while throwing a two-handed weapon is a full-round action. Regardless of the type of weapon, such an attack scores a threat only on a natural 20 and deals double damage on a critical hit. Such a weapon has a range increment of 10 feet.

(emphasis mine). There is no mention of "improvised" anywhere in this text. And since an improvised (ranged) weapon is a defined game term, the common english definition "not designed for" = "improvised" does not apply either.

Improvised Weapons itself states:

Sometimes objects not crafted to be weapons nonetheless see use in combat. Because such objects are not designed for this use, any creature that uses an improvised weapon in combat is considered to be nonproficient with it and takes a –4 penalty on attack rolls made with that object. To determine the size category and appropriate damage for an improvised weapon, compare its relative size and damage potential to the weapon list to find a reasonable match. An improvised weapon scores a threat on a natural roll of 20 and deals double damage on a critical hit. An improvised thrown weapon has a range increment of 10 feet.

(emphasis mine) An astute observer notices that there is no difference between a thrown melee weapon and an improvised weapon when it comes to the mechanical aspects. Both take a -4 penalty on the attack roll, have range 10 and critical 20/×2, which indicates that throwing a melee weapon is probably intended to be an improvised weapon attack.

The most interesting part of this is the first line, however, which forbids you to use anything that was "crafted to be (a) weapon" as an Improvised Weapon. It does not say "melee" or "ranged" weapon or anything like that, just "weapon", which leads to the following RAW weirdness:

• You can not throw that greatclub as an Improvised Weapon and benefit from Throw Anything.
• You can throw that big tree branch you found (which is roughly the same size and form as a greatclub), as an improvised weapon (dealing damage like a greatclub) and benefit from Throw Anything.

This, of course, is silly, and I'll go out on a limb here and say:

RAI: Yes.

I don't have any developer quotes to back this up, but I can't imagine it to be any other way.

Answer 2

I found an official FAQ on the Paizo website where an individual asked if they could use their longspear as an improvised weapon to attack adjacent creatures. Below is their response:

You could choose to wield your longspear as an improvised blunt weapon. In this case, it threatens only your adjacent squares, and not the further squares. If you are wielding it as a longspear, though, to threaten the further squares, then your grip precludes the use as an improvised blunt weapon. The rules are silent on how long it would take to shift between the two, but switching between a one-handed and a two-handed grip with a one-handed weapon like a longsword is a free action (and can thus be only taken on your turn), so it should take at least as long as that, thus preventing you from simultaneously threatening all of the squares at once. Incidentally, using the longspear as an improvised weapon in this way would not allow you to benefit from any magical enhancements it may possess, nor would you add benefits that apply when attacking with a longspear (such as Weapon Focus (longspear), but you would apply any benefits from using an improvised weapon (such as Catch Off-Guard).

Note that not only is the individual allowed to use the longspear as an improvised weapon, but that they could also apply Catch Off-Guard (a feat that works with improvised weapons). I would then think it reasonable to consider the allowing of manufactured weapons (not meant to be thrown) to be thrown as improvised weapons and benefit from the Throw Anything feat.