This question is about 20th Anniversary edition if it helps.

Whether from losing it in battle, or a metis born with one arm - I was hoping to ask if there’s anything explicit anywhere on how this affects them stats-wise?

Whether there’s something written on it lowers an overall stat but rolls are normal, or if certain rolls are at a minus (overall or form dependent wise)?

If not does anyone have any playtested experience about how they homeruled this? For a PC or an NPC.