Offensive Lineup:
A team may elect, for entire game, to bat any number of players, however, it must finish the game with the same number of batters it started with. If a team is unable to continue the game with the number of batters it started with, it is a forfeit. A team has 5 minutes
(upon request from the opposing manager or home plate umpire) from the time of ejection or departure of a player from the line-up t indicate which other eligible player is the substitute for the removed player. A team may bat 9 or all players and they may add players to the bottom of the order during the game with the provision that the team must finish the game no less than the largest number of batters at any given time during the course of the game in the line-up.
A starter in the batting order may be removed and a substitute may bat in that player’s place at any point during a game so long as the starter has had on plate appearance. The starter may return to bat again, but only in the original spot in the batting order, and only after the replacement has had at least one plate appearance. The substitute may not bat again once removed from the batting order. Please remember, only the starter may re-enter during the course of the game. Any other player re-entering the order will be treated as batting out of order under Official Baseball Rules #6.07.
The starter and substitutes are locked into the same spot in the order and cannot bat anywhere else. They become ineligible to bat in any other position in the batting order. The starter and substitutes are considered "in the game," and may not be used as pinch runners as they have already been "used". A pinch runner (as opposed to a courtesy runner) must be someone who has not been in the batting order and will be dealt with under the offensive line-up rule (i.e., that player must have one plate appearance before the starter re-enters). As reference, see Official Baseball Rules #6.07.
A starter (not designated as a non-runner) who is replaced by a pinch runner while on base is removed from the batting order. Once that runner or another legal substitute has one plate appearance the starter may reenter. A pinch runner who does not hit at least once in the spot in the order where the player they are running for batted, shall be considered "out of the game" and may not re-enter.
Defensive Lineup:
All teams have the option to substitute freely on the field in any defensive position except for the pitcher. A pitcher may leave the mound for another position on the field or on the bench but may return only once to their position as pitcher. Violating this pitcher’s rule does not constitute a forfeit, although the pitcher must leave the mound immediately. Free substitution on the Field does not affect the batting order. Defensive positions need not be listed on the line-up card except for the pitcher.