The process of effectively applying techniques for fostering creativity in educational settings is – by nature – multifaceted and not straightforward, as it pertains to several fields such as cognitive theory and psychology. Furthermore, the quantification of the impact of different activities on creativity is a challenging and not yet thoroughly investigated task. In this paper, we present the process of applying the Semantic Lateral Thinking technique for fostering creativity in Creative Stories, a digital storytelling game, via the introduction of the appropriate stimuli in the game’s flow. Furthermore, we present a formalization for a person’s creativity as a derivative of his/her creations within the game, by transitioning from traditional computational creativity metrics over the produced stories to a space that adheres to the core principles of creativity as perceived by humans.