Depends entirely on the organiser, the site and the intensity of the game. If it's a stirling or tier 1 game you're very likely going to have to sort yourself out for everything, though if it's at somewhere like the sandpit depending on the side you're on you may end up living in buildings etc.
All very situational, absolute minimum I would recommend is a good warm sleeping bag, rollmat/campbed, waterproof jacket (that conforms to the dress requirements for the game, no bright orange regatta jackets!), 2 sets of clothing, gun, spare gun, reliable RADIO.
Stirling and tier1 both have fairly comprehensive kit lists on their websites, though again depending on the game they may be too comprehensive!
One thing I won't recommend is ration pack style food, it's something I see every newbie doing; warming up their packets of sludge over a shitty old trangia stove (or similar). Just pack some sandwiches and loads of high calorie snack foods; I like peanuts and haribo for this. If you absolutely MUST have hot food then hotdog sausages heat up really quick in boiling water.