There is no limit to how many players there can be on a lacrosse team, but only 10 can be on the field at once. Also, there are specific rules regarding the number of players on defense and offense.
A lacrosse field is split into halves that determine who is on offense or defense. A team can have no more than six players on offense, usually three attackmen and three midfielders. Also, it can have no more than seven players on defense, usually three midfielders, three defensemen and one goalie. Players can move from one half of the field to the other as long as these number requirements are met.