For reference: http://www.d20pfsrd.com/gamemastering/combat#TOC-Combat-Maneuvers
Earlier this year I read a post claiming this rule could be used as a tactic to escape from an ongoing grapple:
If grappled, one could theoretically ready a one-handed attack against the maintaning grappler to interrupt the maintain check. If the attack hits, the damage would be counted as a penalty to the maintain roll. At least, if I understand the rules correctly.
This seems like a pretty powerful tool that some characters could use to escape from the almost unbeatable CMB/CMD that really large monsters have. In my games there have been plenty of times where a PC gets grappled and realized they have zero chance of breaking free by trying a CMB check. But for melee characters that can hit hard, readying an action to smack the creature for a lot of damage when it tries to maintain the hold next round could be a really effective way to get out of grapples.
My question is does this actually work? Does readying an attack give you the damage it deals as a penalty to the grapplers maintain? Or is this a rule that *only* applies to attacks of opportunity that an unskilled grappler may provoke.
Nope, doesn't work.
But there isn't that big of a penalty for being grappled. You can still just full attack the grappler (though you lose 1 hand) with a -2 penalty.
Being pinned is the real problem, but you can't ready an attack while pinned anyway.
And as for being pinned, this concept can work in the opposite direction.
Character with Imp, Greater and Rapid Grappler gets you pinned.
In subsequent rounds he just uses 1 move action to grapple and 1 swift to grapple. Then he readies an action to grapple you if you break out. You break out, he regrapples, on his turn he spends 1 grapple to pin, rapid grapple to damage and ready the action all over again.
This can actually be a viable tactic for certain builds (like barbarian) that have better CMBs then CMDs. (especially since rage gives -2 CMD and Reckless abandon is another -1 per 4 levels)