Divide into two teams and give each team a filled squirt gun and some index cards and pencils. After each team has created its list of movie titles, familiar phrases, common expressions, etc., one person on the other team must attempt to charade the title or phrase by drawing it on the hot sidewalk with water from the squirt gun. Others on the same team attempt to guess the answer. No talking allowed of course.
Allow two minutes per attempt.
The difficulty and fun of water charades is that on a hot day the water will evaporate quickly on the hot surface, so it is vital the water drawing be completed as quickly as possible.
An alternative method also may be played with ice cubes instead of squirt guns.
