The present paper uses corpus linguistics methods to study a born-digital cultural artifact, namely the collectible card game Hearthstone, released in 2014 and still under active development in 2020. As indicated by the developers’ public statements, such a game, which is framed as an ongoing service rather than a final product, needs to strike a balance between two conflicting constraints: while the game must remain easily accessible at any stage of its development to increase the player base, the player’s experience must be constantly renewed to keep the existing player base from getting bored and leaving the game. In practice, this translates into the regular addition of new card sets by the developer. Our hypothesis is that linguistic traces of these opposite forces can be found in the evolution of lexical diversity in the text of the game’s rules, as opposed to its ‘flavour’ text, which plays no role in the game’s mechanics. To test this hypothesis, a corpus documenting the first two years of the game has been built and it is distributed in open access. The analysis of lexical diversity in these data shows that the rule text vocabulary is both highly controlled and subject to steady diversification. We view these features as reflecting stakes that characterise the ongoing management and development of a game-as-a-service like Hearthstone.