k m8,
this is the lo-down on the 'big game'. Unlike your normal paintball games lasting say...20ish minutes with about 30 players, this game is generally a well organised hundreds-of-players day long game. Unfortunately these don't happen so much in this country (only a handfull a year at the mo') but in America there are bloody loads.
Normally you'll hear the words "scenario game" which go along with the words "big game", and this is just basically a BIG game with a kinda setting - or scenario (ie. one team are the 'DEA' and one team are a bunch of dealers etc. and its meant to be like make believe). So hope that helps, they are generally the highlights of a rec-ballers year.