In the past RPG suggestions have been met with some....skepticism in that such things tend to take participants out of the moment in the same way that tv does.
With over 15 years of RPG activities behind me, I find that statement utterly peculiar. Rant follows, and I know I am off-topic, since the original poster did not want to do an RPG anyway, just a boffer sword duel field (which, in my opinion, sounds extremely fun, but has exactly about nothing to do with roleplaying.)
What many people who have not really played RPGs extensively do not realize is that roleplaying, in its simplest form, is exploring possible worlds and characters through imagining you are them in their situation, and doing this interactively with other people portraying other characters yours interacts with. All the rule-sets and whatnot on top of that are just tools for doing that - sometimes better, sometimes worse. Roleplaying is not all about fantasy, and it is not all about whacking monsters and being a cool hero. The fact that most RPGs seem to be about simplistic heros in simplistic fantasy worlds does not mean that all RPGs are that, any more than the prevalence of bad action movies says anything about movies in general.
RPGs, when played by more or less mature adults with some creative skills (and yes, I do realize that that is quite a requirement, but maybe not as unrealistic in BRC as in the default world ;)) do not take you "out of the moment" any more than any other interactive art/entertainment form does. TV is passive watching, yes. RPGs are active creation the participants are an integral part of. To compare those two does not really work, sorry.
If I was doing a live-action game for BRC, I would not take any ready-made (fantasy or other) world/game and try to adapt it on the playa, for several reasons. Instead, I would like to create a game that would speak specifically for BM citizens, invoke some thoughts and feelings that were specific to the year's theme maybe, something that could be quickly briefed and quickly played. (But I am not, not this year anyway.)
Apologies for ranting, you hit a pet peeve. ;)