Each team consists of a maximum of eleven players. Competition rules may state a minimum number of players required to constitute a team, which is usually seven. Goalkeepers are the only players allowed to play the ball with their hands or arms, provided they do so in front of their own goal.
The basic equipment players are required to wear includes a shirt, shorts, socks, footwear and an adequate shin guard. Players are forbidden to wear or use anything that is dangerous to themselves or another player, such as jewellery or watches. The goalkeeper must wear clothing that is easily distinguishable from that worn by the other players and the match officials.
A number of players may be replaced by substitutes during the course of the game. The maximum number of substitutions permitted in most competitive international and domestic league games is five in 90 minutes, with each team being allowed one more if the game should go into extra-time; the permitted number may vary in other competitions or in friendly matches. Common reasons for a substitution include injury, tiredness, ineffectiveness, a tactical switch, or at the end of a finely poised game. In standard adult matches, a player who has been substituted may not take further part in a match. IFAB recommends “that a match should not continue if there are fewer than seven players in either team”. Any decision regarding points awarded for abandoned games is left to the individual football associations.