Kickball is an outdoor game much like baseball. All of the positions are the same as in baseball (outfield, pitcher, basemen, catcher, batter), but there are no bats or gloves used, and the "batter" must kick a large ball that is rolled toward him by the "pitcher." To put together a kickball tournament, it requires a very large number of participants, and a large open field to play on. Organizing a tournament is a moderately cheap and easy process.
Gather your supplies and make sure you have kickballs and bases that can be used for your tournament. Bases may be nothing more than a spare tire or bucket lid, but make sure you have four of them for a field. If you cannot find a field to play on, you may have to rent a gym space or a baseball diamond for a day. Either way, determine the date in which the tournament will take place, so you will be able to tell the players when to be there.
Ask kids' parents if they are OK with the game, and if so, give them directions to the playing and field. Teams can be set up at the field, but you will need at least 36 players (4 teams of 9). Once everyone has been put onto a team, the tournament can begin. If you have four teams, two of them will play each other and two will watch.
Organize the tournament as a bracket. The winner of the first game will play the winner of the second game, and the winner of this game will be the tournament champion. The loser of the championship game will be awarded second place honors. To determine third place, have the two teams that lost before play each other. The winner will be awarded third place honors.