For meaningful scenarios, creative input concerning possible future trends is crucial. Herman Kahn, the father of modern scenario planning, underlined the importance of thinking the unthinkable in a significant scenario study. Blessed with high intelligence, an assertive personality and the research capabilities of the RAND Corporation,he could rely on genius forecasting. But how can this foresight be creative as well as simultaneously credible and objective if one does not possess Kahn's genius? In this article, we assess the incorporation of expert knowledge via the Delphi technique into scenario planning as a promising option. We discuss possible combinations and identify the span of design alternatives in the existing body of Delphi-based scenario studies through a systematic research review and provide recommendations on how a Delphi-based scenario study should be designed to ensure quality. We recommend focusing on the integration of the Delphi technique only in one phase of the scenario approach. In this way, the design options can be intentionally adjusted to the particular function. We further offer recommendations on how to accomplish this.