Subject says it all. Couldn't find any previous discussion on the topic. It seems that the rules as written say yes, so really I'm wondering if I missed something; though I won't be mad if people discuss RAI.
Grapple: On a successful critical hit with a weapon of this type, you can grapple the target of the attack. The wielder can then attempt a combat maneuver check to grapple his opponent as a free action. This grapple attempt does not provoke an attack of opportunity from the creature you are attempting to grapple if that creature is not threatening you. While you grapple the target with a grappling weapon, you can only move or damage the creature on your turn. You are still considered grappled, though you do not have to be adjacent to the creature to continue the grapple. If you move far enough away to be out of the weapon’s reach, you end the grapple with that action.
Grapple
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Humanoid creatures without two free hands attempting to grapple a foe take a –4 penalty on the combat maneuver roll.
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It's definitely been discussed before, specifically with the Dan Bong.
By the rules, you take the penalty for a net -2 unless you have something that says you don't take the penalty like Grabbing Style.
As for RAI...hard to say.
Having the Dan Bong effectively give a +6 to grapple isn't necessarily intended IMO.
As a GM, I might house rule that a grapple weapon (like a Dan Bong) negates the penalty from not having both hands free or grants a +2 bonus if you can ignore the penalty.
as far as the RAW go, you are correct. I remember this oddity being pointed out that the "dan bong" is a trap. Because while it grants a +2 bonus to grapple, if you're wielding it then you aren't considered to have 2 hands free in which case you also suffer a -4. So, trying to use it to grapple actually results in a -2 penalty, quite the opposite of what's expected.
At least in the case of a reach weapon like the man catcher you gain the benefit of being able to grapple an enemy from a distance, but overall the grapple weapon ability seems pretty poor given that you have to score a critical hit in order to initiate your free grapple check. All at a -4 to boot.
The only way around the penalty would be to get some extra arms (eg vestigial arms) or make it "hands free" (eg. the dancing quality).
Lord Kailas, you can ignore the penalty with Grabbing Style.
It's definitely been discussed before, specifically with the Dan Bong.
the dan bong doesn't have the grapple quality. it happens to give a +2 to grapple checks but this is an entirely different thing from the grapple quality which confers no bonuses to grapple checks as mentioned above.
EDIT: the -4 penalty is only for initiating the grapple, so the dan bong still provides a net +2 for attempts to pin/maintain the grapple which makes sense since it's supposed to help with joint locks. all of that is RAW and seems like RAI as well.
at first glance it seemed wrong that weapons with the grapple quality would suffer this -4 since in theory you're using a device designed to grapple, but i suppose you also have the advantage of being able to apply the weapon's enhancement bonuses on the attempt.
EDIT: the -4 penalty is only for initiating the grapple, so the dan bong still provides a net +2 for attempts to pin/maintain the grapple which makes sense since it's supposed to help with joint locks. all of that is RAW and seems like RAI as well.
I'm not sure, I can't find anything that specifies that the -4 only applies during the initial grapple. I'm looking at the feat Grabbing Master and since you only get the chance to damage or move an opponent after you successfully maintain a grapple this feat would never apply if grabbing style only applies during an initial grab.
If the -4 always applies then, the way the feat is worded it lets you maintain a grapple on 2 opponents with one check. Otherwise, you'd have to release one and it again would never apply since there aren't 2 opponents to damage or move with your successful grapple check.
As a standard action, you can attempt to grapple a foe, hindering his combat options. If you do not have Improved Grapple, grab, or a similar ability, attempting to grapple a foe provokes an attack of opportunity from the target of your maneuver. Humanoid creatures without two free hands attempting to grapple a foe take a –4 penalty on the combat maneuver roll. If successful, both you and the target gain the grappled condition.
the emphasis is obviously mine. anyway, they could have easily said "grapple checks" if they meant more than the one you're initiating with this maneuver and they certainly shouldn't have used the definite article if they meant more than one.
and i'm not sure what you're talking about with grabbing style. it's a style feat. once you activate it, you're using grabbing style until you change styles or combat ends whether you are currently benefiting from it by initiating a grapple or not; so how is grabbing master affected?
they certainly shouldn't have used the definite article if they meant more than one.
Not necessarily.
The here refers to something previously mentioned, it is 'the combat maneuver roll for attempting to grapple'. For an attempt to grapple, there is a singular (definite) combat maneuver roll.
For every attempt to grapple you have to roll the combat maneuver check for that attempt.
Personally, it seems to me that the clearest way to reading it is that if you are humanoid, you take a -4 for each and every grapple attempt if you don't have two free hands.
that's exactly my point. the is a definite article. meaning the maneuver is definitely the one previously mentioned to establish a grapple. the next sentence reinforces this by going on to explain what happens as a result of that specific check.
but that probably isn't the best argument. it's probably more important that the language used is "attempting to grapple". that language is specific unless you think all grapple checks provoke attacks of opportunity.
Since Grappled creatures cannot make attacks of opportunity, it really doesn't matter whether subsequent grapple checks to maintain provoke or not.
And you entirely missed my point. It is THE roll for THE attempt. That doesn't imply that their will ever only be one roll, or one attempt, but that for a specific attempt, there is a one specific roll, and in the question above, that roll takes a penalty.
Attempting to grapple seems to me to more reasonable mean 'attempting to make a grapple check' then it does to mean 'attempting to initiate a grapple.' The grapple rules speak of continue to make a check each round' which strongly implies that the checks you are continuing are the same type of thing as the check you made to began with.
yeah the language shifts to checks each round "to maintain the grapple".
also, there are ways to grapple a creature and not be grappled yourself (or more accurately there are creatures that can do this i'm not sure if there are feats or class features to achieve this), so the scenario can come up where you are attempting a grapple check for instance to escape a grapple and the target of your maneuver (the grappler since that's who's CMD you're rolling against) threatens you. do you provoke?
edit: i could be reading too much into the explicit separation of initiating a grapple and maintaining a grapple in some other modifiers to grapple checks. *shrug*
also, now that i look at the grappled condition, that it says you can't do anything that requires two hands implies that you only need one to maintain the grapple. admittedly, this isn't the strongest evidence that the -4 only applied to initiating the grapple, but it is still evidence in support of that conclusion.