How is rend calculated?

[StreamOfTheSky]

What is the definition of a rend, in terms of the damage amount? I found this: http://www.wizards.com/default.asp?x=dnd/glossary&term=Glossary_dnd_rend&alpha=

But, looking at other creatures' rends (girallon, troll, cave troll), it doesn't look like that's the case at all. The trolls get the base damage dice of both claws and 1.5x str bonus. The girallon gets base damage dice of both claws and 2x str bonus. Where I'm going with this is, what affect does giving one of these creatures Improved Natural Attack (claws) do to this damage? Anything at all? Sorry if this has been asked before.

 

[frankthedm]

What is the definition of a rend, in terms of the damage amount? I found this: http://www.wizards.com/default.asp?x=dnd/glossary&term=Glossary_dnd_rend&alpha=

But, looking at other creatures' rends (girallon, troll, cave troll), it doesn't look like that's the case at all. The trolls get the base damage dice of both claws and 1.5x str bonus. The girallon gets base damage dice of both claws and 2x str bonus. Where I'm going with this is, what affect does giving one of these creatures Improved Natural Attack (claws) do to this damage? Anything at all? Sorry if this has been asked before.

I would say improved natural attack mods the rend dice.

DO check the eratta though, they may have modded the girallaon's rend. MM writers may have given the 4 armed ape a worse rend to represent how brutal a 4 limbed rend can be,