The game can be played with any number of players, but four to ten is probably best. The players should stand in a circle, with each player approximately three feet from the players on their left and right. Play begins when one player serves the balls. To serve the ball, he or she should hold one ball in each hand, and toss them underhanded to two different people in the circle. Each of these two people should then proceed to toss the balls to another person in the circle without disrupting the rhythm of the game. This tossing is continued until a ball is not caught, and play stops. An out is assessed to either the thrower (if it was an errant throw) or the catcher (if a catch that should have been made was not). Once an out has been assessed, play begins again, with the person who recorded the last out serving. Only one out may be recorded per frame.
Play continues in this manner until one person has been charged with three outs. At this point in the game, he or she has lost and must stand outside of the circle. Play continues with the remaining players.
At the point in the game in which only four people remain, the serve is different. Instead of one person tossing both balls to different players, two players who are across from each other start with one ball each and toss them simultaneously. When three players are left, serving returns to the original method, used for five or more players.
At the point in the game in which two people remain, play becomes very different. If one person has fewer outs, he or she throws first. If they have equal numbers of outs, the winner of a best-out-of-three rock-paper-scissors (no shoot) contest will throw first. The players stand three to five feet apart. To throw, both balls are held in one hand and tossed in the air. The other player must catch both balls. If the balls are thrown so that they are outside of the reach of the catcher's arms, it counts as a catch. Next, the roles are reversed, and the second player throws the balls to the first player. An out is charged to one of the players if he or she misses a catch, but the other player makes the catch. As soon as one player accumulates three outs (total, as the outs from earlier in the game carry over), the other player is declared the champion.
The Serve: No out may be charged on the serve.
Mid-Air Collisions and Negative Outs: If the balls collide in mid-air, play stops. Each player who catches a ball after a collision is awarded with a negative out. That is, for each ball caught by a certain player after a collision, that player is allowed an additional out before his or her side is retired. Note, if one player catches both balls after a collision, then he or she is awarded with two negative outs. Also, if the balls collide on the serve, no negative outs are awarded, as no positive outs can be awarded either.
Server Immunity: If after the server throws the balls to two different players, both players choose to throw their balls back to the server, and the server does not make the catch, he or she is not charged with an out, and is given the chance to serve again. If the server does make the catch, play continues as usual.
Putting the Balls Together: If both balls are caught at the same time, they may be "put together," at which point normal play stops. The balls may then be thrown according to the manner in which they are thrown when just two people are left. If the player to whom the balls are thrown does not make the catch, then he or she is immediately awarded with an out. Note that the balls do not necessarily have to be put together. Note that normal play could stop, as the balls are put together, and then begin anew if a player makes the catch and opts to separate them again.
The Ten Foot Rule: The during normal play, the balls may not be thrown more than ten feet in the air. If they are but are caught, play continues. If they are but are not caught, it becomes a do-over and the thrower is chastised by the other players. When the balls are "put together" or when there are just two players left, the ten foot rule is replaced by a twenty foot rule.
The Three Strikes and You're Out Rule: Since no outs may be charged on the serve, it is possible for several serves to be made before play actually begins. This rules stipulates that if a player makes an out-worthy mistake on the serve, he or she is charged with a strike but not an out. If three strikes are accumulated by one player before the balls are successfully served, then that player will be charged with an out. Note that strikes do not carry over to different frames of the game.