I mean where we have basically have all of Konohagakure face eachother save a few i.e.; Hokage, those on official village buisiness, anyone that dosn't want to participate. Anyway, basically the OVA I watched was entitled with Jounin v.s. Genin. Of course Chuunin were allowed to enter along with special Jounin. Now the video in the link I will give you dosn't explain how to win but by the way the game plays I believe it is the first person to gather 5 crystals or something and turn them into the Hokage wins. Now the prize is they get to create a new rule for the village. But seeing as this is a guild I thought possibly we could expand the prize and we could possibly make the prize changin a rule of the guild. But there is one problem, we would have to have some sort of HP system to find out who gets the crystal or not. It isn't any fun when the person willingly just gives up. Then we could just factor in the thing about stats and what not. Okay, enough of my rambling on. Here is the link to the OVA.
OVA