Any hits on the jacket will be easily visible. Any players with wet patches on their flack jackets, are not allowed to fire on an opponent and must return to their home base for a replacement flack jacket. The team that has the most dry flack jackets at the end of the game are the winners. Obviously you can't use this idea if it is raining. This is a great game for hot days on camp.
Teams stand in lines.
They have a bucket full of water at the front of the line and an empty bucket at the rear. The object of the game is to transfer the water from the front bucket to the rear bucket. To do this the team members must pass the cups of water over their heads to the person behind. Empty cups must be passed back to the front in the same fashion. To play the game fairly you could weigh the buckets at the start and finish to see how much water has been lost.