Field lacrosse is a full contact outdoor men's sport played with ten players on each team. The sport originated among Native Americans, and the modern rules of field lacrosse were initially codified by Canadian William George Beers in 1867. Field lacrosse is one of three major versions of lacrosse played internationally. The rules of men's lacrosse differ significantly from women's field lacrosse (established in the 1890s). The two are often considered to be different sports with a common root. Another version, box lacrosse (originated in the 1930s) is also played under different rules.