Hacky Sack Basics provides information on playing hacky sack. The ultimate goal is to keep the hacky sack airborne as long as possible when playing in a group, with completing a "round" meaning everyone has kicked it once and a "double helix" meaning twice. Individual freestyle involves complex tricks. It recommends buying a quality sack filled with sand or beads and potentially rolling over large beads to break them down. Skate shoes or tennis shoes with a flat surface are best for kicking and stalling the sack. Shorts are preferable to pants to avoid restricting movement.