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
Lacrosse in the United States “on the fly” meaning that the players may enter and exit the field during gameplay assuming each team has a maximum of ten players on the field at the time. The game essentially has the same rules as hockey and is played both indoor (box lacrosse) and outdoor (full field). Lacrosse started out as a tribal ritual for native Americans to play before going to war. Differences between groups may have been settled through large, multi-day games covering expansive fields and many players. The game was originally known as stickball. Ever since its creation, it has been considered a collision