Homebrew rules to sunder natural weapons?

[classy one]

I like to break stuff, I like to debuff. I want to combine the two and break limps, claws, legs, hooves, wings, spines etc. anyone made a rule set for this? Natural weapons don't have hardness or HP so how would a homebrewer go about sundering people?

[eftexar]

I don't think damage is the way to go, though there are a couple of different ideas that come to mind.

You could set a hardness, probably by creature size with a table (adding any constitution bonus they might have), and allow a sunder attempt that overcomes this hardness to disable the natural attack for 1 round + 1 round / 5 you exceed this hardness.
You might even allow breath weapons or gaze attacks to be damaged in this way.

Or, setting hardness, create a penalty to attack or damage rolls by the amount you exceed that hardness.

[classy one]

That's a good idea with the size determining the hardness. I'd prolly add 1/4 of the target's HD on there as well. I think the number should be on the high side too since all you need to do is overcome their hardness.

As for damage, you are hitting their body, albeit a non vital part. At least deal a portion of what goes over the hardness. Maybe half?

They can use heal or healing spell or power to regain use of that natural attack.

When sundered it should have some other negative effect like they can't hold onto things (hands) or walk at half speed (legs) or are blinded (eyes). Would need a list of all the types of natural attacks and how sundering it would affect the target.

[Debihuman]

I like to break stuff, I like to debuff. I want to combine the two and break limps, claws, legs, hooves, wings, spines etc. anyone made a rule set for this? Natural weapons don't have hardness or HP so how would a homebrewer go about sundering people?

You could use "called shots" see here: http://www.d20pfsrd.com/gamemastering/variant-rules

Debby