Do you gain a number of arms equal to your character's CB? Or do you then have the Multiple Arms (x) trait where (x) is your CB?

Because if you gained this trait at char gen, as far as I'm reading, you'd only have one arm unless you somehow accrued 20+ Corruption prior to play?

A Mutant player of mine is looking for clarification, and frankly, this has me stumped as to what it's supposed to be at RAW.

From my understanding, it means you'd gain the Multiple Arms (x) trait. So for a character with a low amount of CB at the time they acquire the mutation, they're not really going to see any benefit from the mutation as you'd ideally want CB 4 or higher when you get Multiple Arms. RAW-wise I'm fairly certain mutations are not meant to scale with your CB and are acquired based on your current CB so there's no real chance for the multiple arms mutation to get any better. It gives your player an incentive to get a cybernetic arm though or just shove a sword in their shoulder so they can still fight..