In the game of foot bag you will use your feet and kick or "hack" the foot bag or for future refrence hackysack.
There are several types to this game such as freestyle where the player or players demonstrate their abilities by performing sequences of difficult and moderate moves that will be judged.
There is also one called circle kick (or in slang at school a hacking circle) there are sevral players that will test their skills against one another and even try to get a hack.(which is where each one of the players hits the hack at least once in a sequence before the hack hits the ground.)
Before it gets going too far what has to be told is the game of killer and numbers. In the game of killer you start off with a circle kick and try to hit the other players with the hack that you are playing with. Now it may sound easy but there are rules you have to follow like you will have a set number of times you have to kick the hack before you can kick it at another person to get them out and even if you get that number there is a thing called counter kill where the person being hit will kick the hack before it hits the ground and will not be out... at that time the player countering can kill with only hiting it once.
In the game of numbers you will once again start off with a circle kick but you will also go in a set of numbers starting from 1. The person with 1 will have 2 chances to get that number because it is a new number.(for the future a new number will always have the player with 2 chances to get that number) Now if that person can't get the number in 2 trys the person next to them will have 1 chance to get that person out by getting the number that person could not get...that person will have only 1 chance to get that person out in that round if that person dues not get the number in 1 try the number is again a new number and will give the next player 2 trys to get the number.
Now with bean bag chairs you sit on them. They are made of sevreal different types of fabric and even leather. They are filled with tiny bits of styrafoam and other stuff to help support the sitting person comfortably.