Box lacrosse The roots of indoor lacrosse are obscure, but its invention has been attributed to one Paddy Brennan, a field lacrosse player and referee from Montreal, who, being annoyed by the constant slowing of play from balls going out of bounds in the field game, experimented with indoor games at the Mount Royal Arena during the early 1920s. Joseph Cattarinich and Leo Dandurand, owners of the National Hockey League's Montreal Canadiens in the 1920s, led the participating ice hockey arena owners to introduce the new sport. In the 1930s, 6 v 6 indoor lacrosse came to be played in the summer
Field lacrosse member William George Beers codified the modern game. He established the Canadian Lacrosse Association and created the first written rules for the game, "Lacrosse: The National Game of Canada". The book specified field layout, lacrosse ball dimensions, lacrosse stick length, number of players, and number of goals required to determine the match winner. Field lacrosse involves two teams, each competing to shoot a lacrosse ball into the opposing team's goal. A lacrosse ball is made out of solid rubber, measuring 7.75 to 8 inches (19.7–20 cm) in circumference and weighing 5 to 5.25 ounces (140–149 g). Each team plays with