Soccer, also known as football in some parts of the world, is played between two teams of 11 players, one of whom is a goaltender. The aim of the game is to score goals, but only the goaltender is allowed to use his hands and arms. The rest of the players must use their feet, chests and heads to direct the soccer ball into the opposition's net. The game pauses if a referee calls a foul or an offside penalty.
Soccer is played under the supervision of a referee and two linesmen. It is their job to call penalties and allow free kicks and penalty kicks when particular rules are broken. If more serious infractions occur, referees may issue yellow cards or red cards. If a player is issued a red card, he must leave the game and cannot be replaced, meaning that his team must play with 10 men for the remainder of the game.
Offside penalties are extremely important in soccer. A player is in offside position when there are fewer than two defenders, including the goaltender, between him and his opponent's goal. If the ball is played to a player who is in an offside position, a penalty is called by the linesman and the ball is awarded to the other team.