Box lacrosse (boxla, boxcrosse, or inoor lacrosse) is an indoor version of lacrosse played in Canada and the United States. The game is generally played in summer on an ice hockey rink from which the ice has been removed. The playing area is called a box, in contrast to the open playing field of outdoor lacrosse. Box lacrosse was invented in the 1930s as a way to promote business for ice hockey arenas. Eventually it became the more popular version of the sport in Canada.