Haftpflichtversicherung, as the name suggests, is mandatory for all vehicles and covers the costs of other parties involved in an accident if you are the culprit. Teilkasko is an additional optional option that insures you against additional cases that you, as a Driver, cannot influence. Examples include theft, burglary, broken glass, natural disasters such as hail, floods and rooftop avalanches, and damage from wild animals. Teilkasko costs an extra €90 on average. Vollkasko is also optional and includes Teilkasko plus insured events created by the driver himself: that is, the insurance company will indemnify or repair your car if you are the culprit of an accident. I recommend taking Teilkasko in any case, and if the car is less than three years old and it is expensive, then I recommend taking Vollkasko.