The rules of lacrosse govern the administration and conduct of games, including equipment used. Three organizations write rules for lacrosse played in the United States — US Lacrosse (youth rules for boys and girls, high school rules for girls, non-varsity collegiate rules for women, post-collegiate rules for men and women), the National Federation of State High School Associations (high school rules for boys), and the NCAA (varsity collegiate rules for men and women). US Lacrosse representatives sit on rules-writing committees of the NFHS and NCAA, and the three organizations often work together on rule development and player safety.