Circle Kicking
Commonly referred to as Hacky Sack* this form of footbag involves players passing (kicking) the bag around a circle.
The aim is to keep the bag off the ground for as long as possible using any part of the body except for hands and arms.

A hack is achieved when every person in the circle has kicked the footbag. Although commonly referred to as Hacky Sack, the correct name is footbag.
The name Hacky Sack is a registered trademark of the Wham-O Company.

A relatively new sport 'freestyle' has been described as juggling with feet. Players set & catch the bag with various parts of the body but primarily the top and inside surface of the foot. While the bag is in the air manoeuvres such as dexes (moving leg around the bag), spins and ducks are performed.
Players typically perform runs (or routines) stringing many different manoeuvres together or single big tricks & combos.