Silly party games throw out the rule book, when it comes to adult party ideas. Stuff a sports bag with as many silly clothing items as you can find (or buy from.
This is a game that you will want to play in an open area such as outside or in a Play this game with the same rules as volleyball except with 3 teams. Have 2.
These games are competitive or skill based for the sporty minded campers, youth , or staff. Modify them to be as competitive (or not) as you like.