I am trying to figure out a task/scenario for a locative media experiment. The PLAYLab has an interesting approach:

We have a rigourously theoretical framework, as well as a speculative and design oriented appraoch when designing gaming applications. Observations of live role-playing games provide inspiration and an excellent platform for thinking about new gaming interfaces that are both ubiquitous and tangible.

The "narrative" thing does not interest me that much, but the idea of using live RPG observations as starting point is relevant.