The Offsides rule is one in soccer that benefits the defender, and is a tool in the soccer defender's arsenal. It is usually slanted heavily in the defense's advantage:
There are more than one disadvantage to offsides for the defensemen, but these make sense:
  • There is no offsides on a corner kick. This, of course, makes some sense, since a corner kick is a strange circumstance, where the entire teams squeeze themselves in to a small spot. All bets here are off.
  • Offsides is not called if the person gets the ball by starting on one side of a defender, and running past him to get the ball. This is just hard work, and defeating the defender.

The Offsides rule in soccer is meant to keep the final shot to a one on one match-up between the attacker and the defender (usually the goalie). It is very hard to teach this rule to most new soccer players as it involves a good eye on the field, and a good deal of almost trickery to get two people to run past you. My brother, a referee hates this call since it is almost an opinion of the referee as to where is too far, and what constitutes a threatening move by the offense.

There is also an Offsides rule in American football. Offsides is when either the offense or the defense is over the line of scrimmage before the snap is called. This carries a five-yard penalty, and replay of the down*

*unless the defensive offsides would give a first down to the offense. In this case the first down is awarded.