Background: Due to the increasing usage of online-gambling in everyday life, the relevance of internet-based addiction prevention becomes more and more evident. Interactive offers are of special interest, as they allow for the adaptation of the website content to the user's situation and needs. In order to prevent the risks of problematic gambling the German Federal Centre for Health Education (BZgA) has developed an according offer called "Check dein Spiel" (CDS, check your gambling). Aim: This article gives an overview of the interactive contents of this website and explains how they are used in the prevention of problem gambling and pathological gambling. At first, the self-test is described, which allows gamblers to get an individual feedback on their gambling behavior. Second, the structured counseling program of CDS is reported and experiences are discussed that were made since its online start.