Color Guard
Fill a cooler or bucket with at least as many water balloons as you have players. Select one player to be the ̶0;color guard,̶1; and ask her to close her eyes while the remaining players select a water balloon from the bucket. The color guard then opens her eyes and calls out a color. Any player holding a water balloon of that color must try to get the balloon back into the bucket or cooler without being tagged. The last player left standing gets to be the color guard next.
Splat!
This relatively low-key water balloon game appeals to the simple pleasure of popping the balloons. Players take turns holding water balloons as high as they can above a stretch of pavement or sidewalk, and take turns dropping balloons to make as big a splash mark as they can. Designated ̶0;judges̶1; mark the splash marks with chalk before they disappear and select a winner at the end of the game.
Balloon Sandwich Relay Race
Divide the group of teens into pairs. Each pair must balance a filled water balloon between their backs and try to reach the finish line and back without popping or dropping the water balloon. If the balloon breaks, the team must get another one and start the race over again.
Towel Water Balloon Toss
Divide the group into teams of two or more, and give each team a towel and a bucket of water balloons. Teams must use their towels to launch water balloons toward their opponents, who then try to catch the water balloons with their towels. All teams launch and try to catch balloons simultaneously. The team that can catch the most water balloons without popping them wins.