Are you stuck in a pattern of thinking? These challenge stimuli cards will help you challenge any kind of thinking whether it is about product development, service or social innovation or any other problem or focus that needs new thinking. Challenge cards provide advanced cognitive stimulation and are intended for creative processes with high ambition for novelty. Each card provides four unique cognitive challenges. They are designed ready to print on a duplex printer. I invented this toolkit in collaboration with Søren Hansen and Kreativitetslaboratoriet.