(aka open substitutions). Means you can substitute as many times as you want at allowed times during the soccer game. Pro soccer leagues limit the number of substitutions; most youth leagues do not & many have an unlimited substitution soccer rule. Some youth soccer leagues only allow substituting between quarters, which is not really “unlimited substitution”. Others allow the soccer coach to “sub” any time a goal kick is called (by the other team) on his own throw-ins & other times. (See “Soccer Substitutions” for more details).