Number of Players. There are 11 players for each team, including one goalkeeper who may use their hands within the penalty area (a box within 18 yards of the goal). The other 10 field players in front of the goalkeeper are arranged in any manner, and may not use their hands anywhere on the field.
Forwards need to be fast, and able to move and control the ball well. Often thought of as the "goal-scorers" or "strikers," a team looks to its forwards to be at the right place in the right time to capitalize on opponents' mistakes.
Midfielders (also known as halfback) need superb ball skills, with passing being the most important. This position plays a "transitional" game from defense to offense and vice versa. They should also be the most fit players, as they'll cover the most ground.
Defenders this position's primary duty is to prevent the opponent from having a good shot at the goal. The defender also works to gain possession of the ball and pass it to a teammate for an attack.
Additionally, a Sweeper is a special kind of defender, who should have good communication skills, especially with the rest of the defensive players. Usually positioned behind the other defenders, sweepers also share the leadership responsibilities with goalkeepers.
The Goalkeeper should have excellent hand-eye coordination, as well as ball-control skills with his/her feet. The goalkeeper sees most of the action unfold, and must be able to direct other teammates to the correct positions.
Length of Game. Each game will consist of two halves of 45 minutes, with a 5-minute halftime. Tied games are allowed.
Equipment. All players must have shinguards. Cleated shoes are not mandatory, but are recommended.
Substitutions. Substitutions may be made on a possession throw-in (by the team who has the throw-in), on any goal kick, or when a goal is scored. With the referee's permission, a substitution may be made if there is an injury or if a yellow-card is issued.
Re-starts when the Ball is Out of Bounds
Throw-ins. When the ball goes completely across the sideline, then the team opposite to the team of the player that last touched the ball gets a throw-in. The thrower must face the field of play, with both feet on or behind the touch-line (sideline), and use both hands to deliver the ball from behind and over her head. The thrower may not play the ball again until it has been touched by another player, and a goal cannot be scored directly from a throw-in. With an illegal throw-in, the opposing team gets a throw-in.
Goal-kicks. When the ball has passed completely over the endline, and the ball was last touched by the attacking team, the defending team gets a goal-kick. The goal-kick is taken from the goal area, 6 yards from the goal, and must be kicked outside the penalty area, 18 yards from the goal, without touching another player.
Corner-kicks. When the ball has passed completely over the endline, and the ball was last touched by the defending team, the attacking team gets a corner-kick. The corner-kick is taken within 1 yard of the corner flag, at the intersection of the endline and the sideline. The defending team must remain 10 yards away from the kicker, and there cannot be off-sides on a corner-kick.
Re-starts inside the Field
Free-kicks. With free-kicks, players of the opposing team must immediately move 10 yards away from the spot where the free-kick is taken, until the ball is kicked. The kicker may not play the ball a second time until the ball has been touched by another player. There are two types of free-kicks: "direct" (from which a goal can be scored directly) and "indirect" (from which a goal cannot be scored unless the ball touches another player).
Indirect-Kick Fouls. An indirect free-kick is awarded if a player: (a) commits a dangerous play (playing the ball while on the ground, kicking above the waist, or charging the goalkeeper); (b) commits a shoulder-charge away from the ball; (c) obstructs an opponent when not playing the ball; or (d) commits a goalkeeping foul. A goal can be scored from an indirect-kick only if the ball touches a second player before going into the goal.
Goalkeeper Fouls. An indirect kick is awarded to the opposing team if the goalkeeper takes more than 6 seconds to release the ball after picking it up, releases the ball and touches the ball with her hands before it touches another player, or touches the ball with her hands after it has been deliberately kicked to her by a teammate. A goalkeeper can pick up a ball with her hands if the teammate passes the ball back using her head, chest, or knee.
Offsides. Here's the entire official rule for Offsides, which is the most complicated rule in the game of soccer:
A player is in an off-side position if she is nearer to her opponent's goal-line than the ball, unless:
(a) she is in her own half of the field of play, or
(b) she is not nearer to her opponents' goal-line than at least two or her opponents.
A player shall only be declared off-side and penalized for being in an off-side position, if, at the moment the ball touches, or is played by, one of her team, she is, in the opinion of the referee
(a) interfering with play or with an opponent, or
(b) seeking to gain an advantage by being in that position.
A player shall not be declared off-side by the referee
(a) merely because of her being in an off-side position,
(b) if she receives the ball direct from a goal-kick, a corner-kick or a throw-in.
If a player is declared offside, the referee shall award an indirect free-kick, which shall be taken by a player of the opposing team from where the infringement occurred, unless the offense is committed by a player in the opponent's goal area, in which case the free-kick shall be taken from any point within the goal area.
Off-side shall not be judged at the moment the player in question receives the ball, but that the moment when the ball is passed to her by one of her own side. A player who is not in an off-side position when one of her colleagues passes the ball to her or takes a free-kick, does not therefore become off-side if she goes forward during the flight of the ball.
A player who is level with the second last opponent or with the last two opponents is not in an off-side position.
Shoulder-charge. Shoulder-charging an opponent while going after the ball is permissible. Shoulder-charging an opponent away from the ball is a foul, penalized by an indirect-kick.
Obstruction. Shielding an opponent from the ball while standing or running next to ball is permissible - it is considered "playing the ball", even if you are not touching the ball. Otherwise, shielding an opponent while away from the ball is Obstruction, which is penalized by an indirect-kick.
Direct-Kick Fouls. A direct free-kick is awarded if a player: (a) kicks or attempts to kick an opponent; (b) trips an opponent; (c) jumps at an opponent; (d) charges an opponent in a violent or dangerous manner; (e) charges an opponent from behind; (f) strikes or attempts to strike an opponent or spits at her; (g) holds an opponent; (h) pushes an opponent; or (i) intentionally handles the ball with her hand or arm. A goal may be scored immediately from a direct-kick.
Penalty-kicks. Should a player of the defending team intentionally commit a direct-kick foul within the penalty area, she shall be penalized by a penalty-kick. Penalty-kicks are taken at the penalty spot, 12 yards from the goal. Except the goalkeeper and the player taking the kick, all players must remain outside the penalty area (18 yards from the goal) until the ball is kicked.
Cautions. A player is cautioned and shown a yellow card if: (a) she enters a game without the permission of the referee, (b) persistently fouls other players, (c) dissents with the referee, (d) or is guilty of unsporting behavior. An indirect free kick will be given to the opposing team.
Ejections. A player is sent off the field and shown a red card if: (a) she is guilty of a violent conduct, (b) is guilty of a serious foul, (c) uses foul or abusive language, or (d) is guilty of a second cautionable offense after having received a caution. An indirect free kick will be given to the opposing team. The team with the offending play will have to play with one fewer player for the remainder of the game.