First I know this is a post about Age of Sigmar from a forum about Age of Sigmar, however it is a discussion that it feel is very relevant to this post. Even more so because its quite clear that nearly every person on DakkaDakka has a simplistic (and condescending) attitude towards Open Play. So read on and perhaps learn something new!
http://www.tga.community/forums/topic/9381-open-play-lets-read-the-generals-handbook/
In fact if you'd like to learn more about Narrative and Open Play I'd really check out some posts on The Grand Alliance forum. It seems a little backwards but the
AoS Narrative and Open Play community have been exploring this style of gaming for nearly two years and in my opinion, with greater depth and creativity than has existed in
40k for more than a decade.