The National Federation of State High School Associations has written a set of rules applicable to high school baseball played in the United States. While each state may have its own set of rules that can result in slight differentiation, high school baseball played anywhere across the nation uses similar rules and regulations.
Length of Game
An official high school baseball game is seven innings long. If the home team is ahead after the visiting team has batted in the top of the seventh, it does not have to bat. A game is official after four innings. If the two teams have played four innings and then the game must be stopped because of a weather interruption -- rain, snow or lightning -- the game is considered official. However, if the game has to be stopped because of darkness, the two teams can agree to pick up the game from where it left off if the subject had been discussed prior to the start.
A designated hitter may be used in all games in high school baseball. Unlike professional baseball, the designated hitter does not have to be used in place of the pitcher. The high school baseball head coach can choose to use the designated hitter for the weakest hitter in the lineup. The lineup does not have to include a designated hitter. If the head coach chooses to use all his fielders in the batting lineup, that is OK. However, if the coach wants to use a designated hitter later in the game, he does not have that option. The designated hitter must be used from the start of the game if the coach wants to employ it anytime in the game.
The base runner may not get in the way of or touch any fielder involved in making a play. If the fielder is standing in the baseline, the base runner may think he is entitled to run over the fielder because he is in the runner's direct path to the base. However, the runner must alter his path to the base. If the runner is judged to have interfered with the fielder, the runner is out and all other runners must go back to their original base.