5. The Referee - Well the man in black (or more recently phosphorus green) is probably the biggest "invention" that came with the initial soccer rules constitution and his role is to enforce these official rules of soccer "in connection to the match he has been appointed to".
The center referee is accompanied and helped by two assistant referees (one on each side of the pitch) and a fourth one that handles small issues like showing injury time duration, checking a substitute player's equipment and replacing one of the three main referees if they can't continue the game.
