Cheat Codes
Open the ge3.ini file in the Gothic3/Ini folder and change the following line in Notepad:

[Game]
TestMode=false

to

[Game]
TestMode=true

You can then press [~] (tilde) while playing to bring up the console and type any of the following cheat codes:

God - God Mode
Invisibility - Invisibility Mode
Teach all - Learn All Skills (lowers stats to 0)
Kill - Kills Target
Give - Give Specified Item
Spawn - Spawn Specified Item/Creature