RULES IN BRIEF Only men under 23 years of age may compete, except for three men older than that in squad of 18. Women have no upper age limit but players must be 16 years or over. Players, other than the goalkeeper in his goal area, may not touch the ball with their hands or arms, except for the goalkeepers If a defender kicks the ball back to the goalkeeper, the goalkeeper may not use his hands, but instead must kick it. No player can rejoin the game after being replaced by a substitute. Three substitutions per team per game are allowed. A goal can be scored directly from a kick-off. A yellow card can be given as a warning. Two yellow cards result in a player being sent off A red card, for a serious offence, results in immediate sending-off Players must play the ball not the person; interference with another player is a foul Attacking players are offside when they are in the opposition's half of the field and closer to the goal-line than both the ball and two opposition players.