This paper shows how researchers can combine and exploit mathematical tools still rarely used by historians (topic models, hierarchical classification, self-organizing maps) to study a dated but heterogeneous historical corpus and to characterize its evolution over time. The analysis focuses on changes in the vocabulary used by a set of 21 popular western role-playing video games published between 1992 and 2017 and comprising a total of 17.5 million words. Through this example, we aim to shed new light on the canonical history of the genre and to propose an alternative model to periodization for uncovering the trade-offs and influences underlying the development of each particular game must negotiate with.