What is the obstruction rule in softball?

Answer 1

This rule states that if a defensive player does not have the ball, she cannot stop the runner from reaching the next base. She could stop the player by standing in her way, or putting her leg down to block a slide before she has the ball to tag her out. A catcher can also block the plate by not allowing the runner a clear path to the plate when they do not have the ball. If a player does have the ball, they are allowed to block the bases though.