Women’s lacrosse is played with two teams of twelve players on the field plus up to six substitutes. The players are grouped into three offensive players, four defensive players (including the goal keeper), and four mid-fielders and a center. At no point may a team have more than seven players goal side of the attacking restraining line and at no point may a team have more than eight players goal side of the defensive restraining line. Typically the attackers do not go below the defending restraining line, and the defender do not go above the offensive restraining line, but there are no rules that explicitly prohibits this.
The offensive object of the game is to put the ball into the opposing teams goal using your crosse. The defensive object of the game is to prevent the opposing team from scoring and retrieving the ball from their possession.
When you have the ball in your possession you are free to run as far as you wish, pass the ball or shoot it at the goal. A defending player may attempt to knock the ball away from your possession by hitting your crosse with theirs. This is called checking. However this must be done in such a way that there is no danger to the opposing player. The defending team may also attempt to intercept any passes with their own crosse. However at no point may any players use their hands to manipulate the ball except for the goalkeeper, which may use the hand to save a shot.
There are two groups of fouls, minor and major fouls. If a player makes a minor foul the fouled player gets a free position where all players have to move four meters away from the player. The fouling player must step back four meters in the direction she came from. If a player makes a major foul then the fouled player also gets free position, but the fouling player has to start four meters behind the fouled player. The fouled player may continue play at the whistle by either running with the ball or passing it (i.e. it is not a free throw, but a free position).
The ball is solid rubber, and a bit bigger than a tennis ball. When propelled it has the potential to injure players. As such safety equipment must be worn to prevent injury. However since the rules regarding physical contact is much stricter in woman’s lacrosse than in men’s, the mandatory equipment is limited to tooth guard. However eye guards and good gloves are highly recommended. A nose guard may also be worn. Helmets and full face masks are prohibited for field players.
The above is a quick run-down of the most important parts of the game. The complete rules may be found on the Filacrosse website.