The offside rule is one of the oldest football rules, but is still a much discussed rule. This is probably because of the relatively complicated set of provisions provided by the sport's law-making body, the IFAB for deciding if a player in an offside position is actually guilty of an offside offence by becoming involved in active play. It can also be a difficult decision for the referee or assistant referee to make as they need to watch the ball, the player playing the ball and also the attacker who is seeking to receive the ball at the same time. 