Great question. First of all - don't drop your device! :)
Okay .... now that we have that off our chest let's answer your question.
Our official policy is: "All case-mate products are fully guaranteed against defects in materials or workmanship. Our guarantee does not cover product damages that may have resulted from normal wear and tear or misuse/abuse or modification of the product. Additionally, the warranty does not cover damage to your device as a result of the use of any Case-Mate product."
Our cases are designed with impact resistance in mind. Clearly we offer different levels of protection for your device. We want to help you protect it. Bottom line, any time a device is dropped, even from the smallest of heights, there is risk of damage. There is not a case on the market, from any case manufacturer, that can guarantee you 100% protection. Make the best case choice for your lifestyle!!