Lacrosse in the United States side of the field at all times. They must also have three players (usually three attackmen) on their offensive side of the ball at all times. The remaining three players (usually midfielders or middies) are free to roam the field as they please during the game. There are ten players on the field at a time. Still each team is allowed a maximum of seven players on their half of the field at a team and six players on their opponents’ side of the field at a time with the goalie being the extra man. Like hockey, substitutions are considered
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