I quoted IUS above - it states that you do not provoke attacks of opportunity from armed opponents when you attack unarmed.
Those are the words it uses.
How is that different from your Improved Grapple argument?
In my post right before yours, I pointed out, that while IUS negates the AOO for attacking an armed opponent while armed, it would not stop the AOO by KS because KS allows the person an AOO whether the attacking opponent is armed or unarmed. IUS considers an unarmed person armed so they no longer draw AOO for making unarmed attacks. KS grants AOOs for armed or unarmed melee attack rolls, so IUS wouldn't negate it.
With IG, it specifically states that it negates AOOs for starting a grapple. IG specifically prevents AOOs drawn by making grapple attempts. So IG bypasses KS. KS does not prevent both because those two feats do different things. IG prevents KS because it specifically allows grapple attempts without drawing AOO. IUS does not prevent KS because it only treats unarmed attacks as armed attacks (which has the effects of eliminating AOO when attacking an armed foe unarmed), it does not specifically prevent AOOs for making an unarmed attack.
I’m going to side with the fact that KS trumps the Improved **** attacks
That is not a fact. That is your opinion. KS states it grants an AOO for successful melee attacks. IG states that it prevents AOOs for grapple attempts. So, IG would prevent the AOO. You can have it your way in your game, but that would be disregarding the rules of the IG feat as they are written.
For example if you were to have KS and go up against an opponent w/o Improved Grapple and they try to grapple you, would you get two AoO? No you would not, as dictated in the PHB you would only receive one. However conceptually you would get two AoO. And continuing with my conceptual thought process the Improved **** would only eliminate one of those two AoO. Hence KS would still work.
No, you wouldn't get 2 AOO, conceptually or otherwise. In that situation, there maybe two conditions for an AOO, but it would be only one AOO as the two conditions are exclusive and independent of each other. IG negates both of those conditions, as long as a grapple attempt is being made. If you had IG and didn't try to grapple, then, yes, AOO as normal. But IG specifically removes the condition of drawing an AOO while attempting a grapple.
The Improved XXXX feats negate the AoO for that particular action (Attacking unarmed, attempting a grapple/trip/disarm), but KS would still allow an AoO if the opponent hits.
You have it right except for the grapple. See above for reasons why. IG negates AOOs for grapple attempts, period; whether the attempt succeeds or fails.
Question. Is a successfull Trip a true Hit? How about a Disarm or Sunder? Grapple is, because you deal damage and are directly attacking the opponent. The others are not quite as clear.
This depends on your definition of a "hit". Since with Trip, Disarm, Sunder and Grapple, you are not inflicting damage. Grapple is not a hit because it does not, in and of itself, inflict damage.
Hmm. You made a couple more mistakes while disagreeing with me.
Hype already pointed out one. The other is that you retain your Dex bonus to AC against someone you're grappling.
In the example I stated, it was about a pinned opponent. A pinned opponent is immobilized and, being unable to move, does not get Dexterity bonuses to AC. In fact, an immobile character would have a Dex of 0, so he would have a -5 penalty to AC, and thus be easier to hit. No mistake on my part. However, you can feel free to disagree with me about the penalty to AC since that is not explicitly stated as a consequence of being pinned. However, unless I am mistaken, there are parts of the PHB and/or DMG that state that immobile things have an effective Dex of 0.
Originally Posted by Hypersmurf
Karmic Strike allows an AoO any time you are hit with a melee attack. Either this is prevented by both IUS and Improved Grapple, or by neither.
Yep.
Nope. That is Hypersmurf's own opinion and your agreement with him. Nothing more. To understand why IUS fails against KS and IG doesn't read at the top of this post.