I read the background that by default most space marines are only going to gain cybernetics as bionics to replace body parts lost in battle and not through voluntary surgery.
"Most" does not cover all though. The techmarines have guidelines of one free bionic when they reach certain levels of reknown. However there aren't similar guidelines for the Iron Hands and other machine-friendly chapters. So I'm trying to work out what is a reasonable rate for an Iron Hands in the Deathwatch to acquire cybernetics, because they *do* undergo voluntary replacement of perfectly good limbs and organs to add functionality and durability.
A few options that come to mind:
1. Use RAW and acquire as many cybernetics per mission as the requisition will allow. Seems dodgy to me by background but technically possible.
2. One cybernetic per successful mission.
3. Copy techmarine guidelines.
4. Leave the decision entirely to the discretion of the Iron Fathers (i.e. the GM via NPCs).
I'm currently leaning towards one cybernetic per successsful mission but I'll be talking to the GM about the matter and I'm curious as to what others think about this.