The
official soccer rules are called the "Laws of the Game" and are revised
annually by FIFA.
Typical adjustments are field sizes, game lengths, number of players per team,
the number and frequency of substitutions, "offside" is sometimes
not called, and slide tackling is sometimes not allowed. Field sizes, ball sizes,
length of games & rules vary by age group. The FIFA rules do not require
separate teams for girls and boys, but many soccer clubs and associations have
separate leagues for boys and girls.
