I want to take a monster out of the bestiary and add a second set of arms. Can anyone point me to where it tells me what it's advantages and new CR would be?
Thank you in advance.
Bump.
The real question is, what can it do with the extra arms? Are you going to be wielding more weapons, I figure?
Give the monster extra attacks with its arms, then calculate the average damage if all of the attacks were to hit a target. Then look on Monster Statistics By CR table in the Monster Creation rules and find out what CR the new average damage output equates to. You may want to adjust other statistics to make the new monster fall in line with the new CR or you may decide the new Average Damage does not warrant a CR change.