Law 2 is the ball. The ball must be made of a leather substance, weigh between 14 and 16 ounces and have a circumference of between 27 and 28 inches. It is advised to have several back-up balls to help speed up play, or in case the ball is kicked into an area where it would be hard to reach.

Law 3 is the number of players. Teams begin play with 11 players (10 field players and 1 goalkeeper). Teams can play with as few as 7 players on the field, however, if a team drops below 7 the game will be stopped. In official international matches teams are limited to 3 substitutions per match. In Major League Soccer teams are allowed 3 substitutions and a 4th for the goalkeeper. Once a player has been substituted, he cannot return. Players cannot leave the field or return to it without the permission of the referee. If they do, they could receive a yellow card. The referee signals a substitution by holding the flag at both ends over his head.

Law 4 is player equipment. The basic equipment a player need to play soccer is a shirt, shorts, socks, shin guards and some type of foot gear, such as cleats. Shin guards must be worn at all times and be covered by the socks. The must provide reasonable protection and be made of rubber or plastic. Players are not allowed to wear anything the referee considers dangerous, such as jewelry. Goalkeepers must wear a color that distinguishes them from other players and the game officials. Referees usually do pre game inspections to make sure teams are following the laws and that the studs on the bottom of cleats are plastic and not metal.

Law 5 is the referee. The referee is called the man or woman in black, or the man or woman in the middle. What he or she says is final, even if he or she is wrong or mistaken. Referees usually do not run straight up and down the field, they follow a diagonal system from one end to the other. They will either whistle for stoppage and start of play, mostly for fouls, or signal direct and indirect kicks as well as penalty kicks. There is no rule that prohibits a referee from talking to the players. The duties of a referee include enforcing all laws, which include making decisions on calling off a game, making decisions on whether and injured player should be removed from the field, ensuring the safety of the players, being a timekeeper and keeping a record ofthe game. Once a game is over, the referee must file a match report with proper authorities, detailing any disciplinary action he or she may have taken.

Law 6 is assistant referees. Assistant referees have flags in their hands, and run up and down either side of the field following even with the path of the ball. They signal which teams gets possession of the ball when it goes out of bounds and results in a corner kick, goal kick or throw in. They also let the referee know when a play is offside. They do this by keeping in line with the last defender so he or she is able to be in a good position to make an offside call. They also alert the referee when a foul is committed that was out of his or her view. The fourth official usually sits on the sideline in the middle of the field and handles the game's paperwork. This includes regulating substitutions, posting any added injury or stoppage time, and being ready in case the referee or one of the assistant referees does not show up or is injured during the game