The following is a very simple summary of the key laws of the game of football, hopefully written in an easy-to-understand way.
The playing area ('pitch') must be rectangular and be between 90m (100yds) and 120m (130yds) long and between 45m (50yds) and 90m (100yds) wide. The end lines are called goal lines and the side lines are called touch lines.
The ball must be spherical with a circumference of between 68cm (27in) and 70cm (28in) and a weight between 410gm (14oz) and 450gm (16oz).
Teams / Players
A match ('game') consist of 2 teams, each with no more than 11 players – including a goalkeeper ('goalie') – and no less than 7 players.
Basic kit consist of a shirt, shorts, socks, shinguards and boots / shoes. Goalkeepers must wear colors different from other players – including their own side – and match officials.
Each match is controlled by a referee supported by 2 assistant referees. He stops the game by means of a whistle for any infringement. He also acts as timekeeper. The assistant referees indicate by flag when the ball is out of play. They also flag when they see infringements that the referee may not have seen.
A game consists of 2 halves of 45 minutes each, with an interval (half-time) of a maximum of 15 minutes. The referee may add on additional time at the end of each half to compensate for time lost through injuries, substitutions and players' deliberate 'time-wasting.'
Starting the Game
A coin is tossed to decide which team gets to choose which goal to attack. The losing team gets to take the kick-off to start the game. The teams change ends for the second half. A kick-off is also used after a goal is scored.
Ball Out of Play
A ball is out of play ('out') when the whole ball has crossed the goal line or touch line.
A goal has been ranked when the whole ball has crossed the goal-line between the goal-posts. The team scoring the most goals wins. If both teams score the same number of goals – or either team scores – the game is drawn.
A player is penalized for offside if at the instant the ball was played by a team mate, the player was actively involved in the play and did not have 2 opposing players between him / her and the opposition's goal line. The player is not in an off position if he / she is in his / her own half, or, is level with the second last opponent, or, receives the ball from a goal kick, corner kick or throw-in. An indirect free kick is awarded for offside.
Free Kicks and Penalty Kicks
There are 'direct' and 'indirect' free kicks. These are just some of the offs for which a direct free kick is awarded: –itting, kicking; tripping; pushing; deliberate hand ball; etc. Similar to an indirect free kick we have: – dangerous play; impeding an opponent ('obstruction'); a goalie holding the ball for more than 6 seconds; a goalie handling the ball after it has been passed to him by a team mate, etc.
At the subsequent free kick, all opposition players must be a minimum of 9.15m (10yds) from where the ball is placed. A penalty kick is awarded for any infringement which takes place inside the penalty area for which a direct free kick would normally have been awarded if it had occurred outside the area.
Awarded to the defending team when the whole of the ball crosses the defending team's goal line – not between the goal posts because that is a goal – after having been last touched by an attacking player.
Awarded to the attacking team when the whole of the ball crosses the defending team's goal line – not between the goal posts because that is a goal – after having been last touched by a defending player.
Awarded to a team when the whole ball crosses a touch line after having been touched by a member of the opposing team.
The above should be sufficient for folks, new to football / soccer, to be able to follow and enjoy this fabulous game. Good spectating!