Play as dodgeball, but divide into even teams (or evenly matched!*). Each team standing in one-half of a marked court (e.g. tennis, badminton, volleyball courts). Teams then take it in turns to throw a softball at the other team from their side. Players when hit below the knee either sit down where they are or join the other side. This becomes much more difficult and fun if more than one ball is put into play.
*if you have some players who are obviously likely to be better that others, eg adults against children, mix the teams so either equal numbers of adults and children on each team or you can sometimes arrange it so it’s children versus adults. Obviously though better to have only a few adults against many children.