Slack ball (also sometimes referred to as Slack disc as it's played with a flying disc) is a flying disc variant that can be played with any number of players greater than two. There is no set boundary for the slack ball field, although physical realities of the playing area can impose practical limitations on this rule. The object of the game is to be as lazy as possible, i.e., not to move.
Start At the start of the game, the players spread out on the field according to their own preference, although an ideal allocation has every player of an equal distance to its nearest neighbor. One player starts with the flying disc, chosen by whoever has the flying disc at the start of the game. Players remain seated throughout the game unless required to do otherwise by the rules.
Play Play begins with the player with the disc propelling (passing) it to another player. After the first completion, play continues similarly, with the player possessing the disc propelling it to another player, but with the restriction that a player may not return the disc to the player that passed it immediately prior (the no-backsies rule). If the disc is not received by another player after being passed and before it stops moving in relation to the field, the nearest player must make any practical attempt to retrieve it. If the nearest player is able to legally retrieve the disc, the pass is considered completed, and play continues. If the nearest player is not able to retrieve the disc legally, the at-fault player must move to where the disc landed and maintains possession with no-backsies still in effect (if the thrower is determined to be at-fault, the incomplete pass does not count for determining backsies).
The at-fault player is the last player for whom the disc was realistically catchable. Contact with the disc indicates res ipsa loquitur that it was catchable, although throwing the disc with speed at a player too close to reasonable protect itself is strictly prohibited and you should not play with such people. If no other player has been determined to be at-fault, the passer--being the last person to have touched the disc--is determined to have thrown an uncatchable pass and is therefore at-fault.
Scoring A player loses a point whenever it is determined that the player is at-fault. If the thrower is determined to be at-fault, this value is doubled. A player receives a bonus point for passing to the farthest neighbor. The target of the pass is determined by who receives the pass in the case of a completion, or the at-fault player in other cases.
Players who keep track of the score have not obtained slack, and therefore cannot win in slack ball. Purists also argue that even acknowledging that a score exists indicates a failure to achieve slack. Praise Bob.