James Wallis uses genre as the fulcrum for balancing game rules and narrative structure in story-telling games, which he differentiates from RPGs through their emphasis on the creation of narrative over character development.
The source is the essay-review on www.electronicbookreview.com written by James Wallis.
"In the ongoing debates about storytelling and narrative in games, the various commentators often overlook a key point: even in the most cutting-edge examples of the state of the art, it is not the players who tell the story, it is the game. Whether computer games with a narrative element, board games, card games, or face-to-face role-playing games, the essential plot and structure of the narrative is predetermined before the game begins, and cannot be altered."
"Human beings like stories. Our brains have a natural affinity not only for enjoying narratives and learning from them, but also for creating them. In the same way that your mind sees an abstract pattern and resolves it into a face, your imagination sees a pattern of events and resolves it into a story."
"the game's mechanics must take into consideration the rules of the genre that it is trying to create: not just the relevant icons and tropes, but the nature of a story from that genre. A fairy tale has a very different structure and set of requirements than a horror story or a soap opera, and a game must work to replicate that. "
"In most games, the structure is simply the way the game is played. In story-making games, it is also the principal way that the narrative shape of the story is formed (...)."
"Structure is not the same thing as rules. (...) That's how the game plays. It's not how the game works."
"The key to a successful story-making game, at least in the ones that have been released so far, is simplicity of design. (...) it does mean that rules have to be integrated with structure and genre to form a coherent package. I am a self-confessed proponent of "elegance through simplicity" in game design, and I realize that this doesn't fit every taste, or every style of game. "
All quotes were directly pulled out of the essay.
Although many issues about how we can construct and analyze electronic narrative remain to be settled, it is clear, then, that a central concern will be the ability of these game narratives to create the emotional impact inherent in our involvement in a story. Emotional involvement is especially important for the interactive text because the user must be prompted to act and move through the text to a degree not required by more traditional reading. In this essay, I would like to consider how electronic narratives balance interactivity and emotional force. Doing so means thinking about emotional involvement and its relation to narrative teleology, as well as its tolerance for interruption by everything from writerly asides to interactive play. To investigate this, I will draw not only on hypertext and computer games but also on American metafiction, which I will show confronts the same problems of emotional force within interactive or game-like patterns. (Source: Introduction to the essay)