Among the many things to be addressed in ver2.0, Incapacitation is one I am especially happy to see recieving some attention. This was mentioned in one of the PDF files:
So, in order to help the devs develop some of the most interesting encounters, I wanted to start this thread devoted entirely to brainstorming ideas for Incapacitation.Incapacitation of body parts for boss fights, encouraging party members to focus on single targets for more engaging battles.
I'll start by posting the link to the concept art PDF here.
Outside of the Primals, there are a few monsters in those pages, more specifically, The Chimera (Page 11), The Suit of Armor (Page 12), The Cyclops (Page 13), and, The Behemoth (Page 18).
The Chimera:
The obvious and most unique characteristic of the Chimera is its 3 heads. So, it follows that the most obvious method of incapacitation involve the 3 heads. The 3 heads each being distinct from one another would have distinct abilities as well, and one suggestion would be to have the two 'outside' heads be severable, as opposed to merely stunning. By severing the heads devastating abilities could be locked out. Much like the FFXI Hydra, these heads may also hold the ability to regenerate periodically, requiring the constant attention of the adventurers.
The Cyclops:
The Cyclops' Eye has to be the target, but it should be handled carefully. It would be silly, considering the size of the monster, for adventurers to simply use Skull Sunder II, for example, to incapacitate its eye considering their attacks would not rise above the waist. So, I would suggest a Compound Incapacitation, targetting first the legs and second the Eye. Players would first incapacitate the legs, bringing the Cyclops to his knees or completely down to the ground (whatever allows for their attacks to be within range of the Eye). Once the Cyclops is down, Players would then proceed in blinding the Cyclops. Now, after being blinded, the Cyclops would engage in a fit of rage, blindly thrashing about. In order to survive the adventurer's flee until the Cyclops' fit is over and his stamina depleted. At this point, the Cyclops would attack slower and be less accurate.
You can also make up your own monsters as well;
I posted this thread awhile back to offer some potential ideas.