Equipment:
swimming pool, any size (it's for all ages)
water balloons
kids and/or adults

Description:
Fill up as many water balloons as desired, then get everyone in the pool (or at least around it) so they can grap a balloon and throw it at someone. If it hits the water, it may not bust, so you can throw it again. This game is for fun only because you're going to get wet.

Other comments or suggestions:
My 3 year old and thirteen year old love to play this. Every summer they can't wait for the pool to go up. Their dad can be mowing the lawn and even he will get involved.