This thesis studies how serious game developers can develop robust business models with regard to future uncertainties that these developers must be able to deal with. Twelve in-depth interviews were held with managers, owners, and entrepreneurs of serious game developers in the Netherlands to identify and describe in detail the future uncertainties that the industry faces and to form insights about various business model elements. During the interviews, a PEST analysis (Political, Economic, Social, and Technological aspects) was done with the participants to identify the uncertainties and the STOF business model ontology (Product, Technology, Organisation, and Finance domains) was used to structure a discussion about the business model elements. 25 Uncertainties within the industry are identified and described, and 34 business model elements are examined. Five uncertainties are chosen as input for a Business Model Stress Test. This resulted in 212 insights about how the 34 business model elements hold against the five selected uncertainties. These insights can be used as a basis for serious game developers to construct and test their own business model and do business model innovation.