As long as it is within the sidelines and goal lines — which form the rectangle of the field — players can control the ball with any part of their bodies except their arms. Within their respective penalty areas, the goalkeepers can also use their hands. For more on the areas of the field, click here.
When the ball leaves the field of play any one of three things can happen:
The Throw In
If the ball leaves the field along one of the touch lines — the two longest lines that run parallel to the goal lines — it is put back into play with a throw in. The throw in is awarded to whichever team did not touch the ball last before it went out.
To perform a legal throw in, a player must keep both feet on the ground behind the touchline near the spot where the ball went out and begin the throw with the ball behind his head. The player must also have two hands on the ball. If the referee deems that a “foul throw” has been committed, he may award a throw in to the other team from the same spot.
The Corner Kick
If a player puts the ball out along his own goal line, the opposing team is awarded a corner kick. On those plays, the ball is placed at the angle formed by the touch line and the goal line and kicked into play.
These are frequently good scoring opportunities and teams usually choose to swing the ball toward the goalmouth to create the most danger.
The Goal Kick
If a player puts the ball beyond the opposing team’s goal line (and not in the goal), the opposing team is awarded a goal kick.
These are usually taken by the goalkeeper, though there is no rule against an outfield player taking it. The ball is placed anywhere within the six-yard box and kicked into play.