Hacky Sack (also known as "Hackey Sack") is the trademarked name of a type of footbag.
The name "hacky sack" came from the 1972 inventors of the Footbag, John Stalberger and Mike Marshall.[1] Although Marshall suffered a fatal heart attack in 1975, Stalberger continued the business.[1] At a later date, Stalberger sold the title to Wham-O. The name Hacky Sack has become a genericized trademark, and can refer to either the footbag or a footbag game. The classic hacky sack circle consists of two or more players that keep the footbag off the ground without using their hands. Some common tricks include stalls, bag daggers, lifts, loops, ham spalts, and milk tosses.
The idea of the game is similar to traditional Asian games of kicking the shuttlecock, known as Jianzi and Chapteh. In Korea it is called Jegi chagi (제기차기). The game is also similar to some South East Asian games, such as Sepak Takraw and Sipa.
The same principle is applied in football-playing countries with footballs.