Bouncy ball is a minor variation on the straight field battle in which one (or more) fighter starts out on no team, the bouncy ball. Each time the bouncy ball is killed, they come back to life on the team of their killer. Since this can happen repeatedly, they can "bounce" back and forth between teams over the battle.
Fighters: any number. For small numbers, this works great to even out teams when there are an odd number of fighters.
Teams: any number, of equal size and strength.
Field: any of sufficient size.
Regen: none, usually, except for the bouncy ball.
Rules: The bouncy ball starts out on their own team. The bouncy ball can win the game if they are never killed. It helps to choose a relatively skilled fighter to be the bouncy ball, since this makes them both a valuable addition to a team, but also a risky prospect to try to "capture". When killed, the bouncy ball regens as decided by the marshall (such as shouting "3, 2, 1, I'm alive!"), and announces their new team. This can happen any number of times during the game.
Any number of bouncy balls can be used, though usually only one is chosen, to even out teams.