Bone snapping fun!

[ARandomGod]

Well, that part's really easy, given the mechanic. Two points of Con damage will heal with two days of rest, or one day under the care of a competent healer ...

Um ... OK, whatever.

Yup. But then it's pretty clear that 'people' heal faster in the magical atmosphere that surrounds the 3.X world than they do in the real world.

Ferrix's version seems relatively balanced to me. It's still going to be a very strong feat, and against a character of level 10 or more trading 3d6 for 2 con damage is a deal. Get up to level 20 and it's very good. I'd probably want some further limitation, like limiting it to once per round as opposed once per sneak attack.

 

[jaker2003]

we could maybe throw Power Attack into the prerequisites . . . I mean, bones aren't really that soft.

 

[GoodKingJayIII]

The Con damage is abstract. Comparing it to actual bone-breakings in real life is probably not realistic. I think in that way the flavor fits the 3.x setting.

However, it is a pretty nasty feat. Even Ferrix's version is very good. Were I a rogue player I'd be itching for this feat. Con damage is simply brutal in DnD, no bones about it. To add to Ferrix's version, I'd add that this attack deals no hit point damage. As has been said many times, this feat simply gets better against higher-level foes, so I think hp damage on top of Con damage is a bit much. I might also require the Fort save, as above (though if no hp damage is being dealt, I'm less inclined to this solution). Consider something like this as well:

Shattering Strike
Your sneak attacks target vital bone or supporting structures, crippling your opponents
Prerequisites: +1d6 Sneak Attack, base attack bonus +4, Str 13
Benefit: If you hit with a sneak attack, you may choose to forgo +1d6 of sneak attack to cripple your opponents. If the attack hits, the opponent takes a -2 penalty to AC and a -4 penalty to all physical skills. Treat these penalties as ability damage for the purposes of natural healing, however they can also be healed by any magical healing, such as a cure spell (1 penalty removed per point of healing, removing the skill penalty first, then the penalty to Armor Class).
Notes: Because it is a sneak attack, your target must be susceptible to sneak attack damage, thus undead, constructs, and other creatures immune to critical hits and sneak attacks are not affected by a shattering strike.

It's a bit more complicated than the above versions, but I also think it sticks to the flavor of the feat, is much less powerful than dealing Con damage, and is still useful.

 

[Goolpsy]

Seems abit to overpowered

Try this

Shattering Strike
Your sneak attacks target vital bone or supporting structures, crippling your opponents
Prerequisites: +3d6 Sneak Attack, base attack bonus +4, Str 15, Power attack.
Benefit: If you hit with a sneak attack, you may choose to forgo +3d6 of sneak attack to cripple your opponents. If the attack hits, the opponent must make a fortitude save of (10 + Half level + str). If he fails the save, he takes the damage + 1d4 point of con damage. If he succedes, he jsut take the regular damage (still -3d6 of sneak attack)
Notes: Because it is a sneak attack, your target must be susceptible to sneak attack damage, thus undead, constructs, and other creatures immune to critical hits and sneak attacks are not affected by a shattering strike.

or

Shattering Strike
Your sneak attacks target vital bone or supporting structures, crippling your opponents
Prerequisites: +3d6 Sneak Attack, base attack bonus +4, Str 15, Power attack.
Benefit: If you hit with a sneak attack, you may choose to forgo +3d6 of sneak attack to cripple your opponents. If the attack hits, he takes the damage + 2 point of con damage.
Notes: Because it is a sneak attack, your target must be susceptible to sneak attack damage, thus undead, constructs, and other creatures immune to critical hits and sneak attacks are not affected by a shattering strike.

 

[Murazor]

As written, way overpowered.

Personally, I'd be very much tempted to link it to Stunning Fist. Probably something like:

Shattering Strike
By combining your knowledge of vulnerable areas in your opponents and the flow of Ki, you are able to deliver attacks that can literaly snap bones with but a touch.
Prerequisites: +3d6 Sneak Attack, Improved Unarmed Strike, Stunning Fist
Benefit: Whenever you are in a position to sneak attack an opponent, you may forego +3d6 sneak attack dice and one of your uses of Stunning Fist for the day, to deal 2 points of Constitution damage in addition to your normal damage.
Notes:Only works against opponents susceptible to sneak attacks. This also counts as a use of Stunning Fist, and can thus only be used once per round