If you want to drastically expand your gameplay after applying the core performance fixes, the community has built excellent content expansions:
Brings back classic armors, items, and visual styles from Gothic 2 to make the world feel more familiar. SГєbor: Gothic.3.zip ...
Because I cannot verify the exact origin or safety of this specific archived file on your computer, I strongly advise against opening or extracting it. If you want to drastically expand your gameplay