1. Some excellent discussion between Cole and Géza Echs buried here: http://www.therpgsite.com/showthread.php?t=20020 They talk about whether the action of an RPG session can be compared to a camping trip, or a narrative about a camping trip.
2. Excellent post by Drolyt, which explains something I touched on in the above thread, only much more clearly than I did: http://www.tgdmb.com/viewtopic.php?p=335116 He talks about cops & robbers vs. chess vs. D&D.
3. It all goes back to ritual as discussed by Chris Lehrich.
See also Magic Circle.
The hard issues here are, first, the alleged distinction between "imaginary events" and "narrative." See also: speech-act. Arguably ritual/roleplay is an area where speech acts are vastly expanded, and they act on complex constellations of concepts.
Second: the alleged identification of player with character.