The following rules are provided as an extension of the general rules of baseball and acts as an alteration to the rules of Major League Baseball. Should any conflict result from any ambiguity of these rules, any interpretations or rulings should be made by a league official.

To be eligible to participate in an OABL sanctioned games, every player must meet the following criteria: They must have reached 18 prior to the first game of the season. They must complete the online registration and agree to the liability agreement. They must pay any applicable player and/or league fees. They must be elligible to enter the premises of city parks and school campuses in the states of Iowa and Nebraska. The OABL reserves the right to ask for valid photo identification to verify a players birthdate and information. Managers have the right to question any player's eligibility to play at any time. Any ineligible players found playing will be suspended for the entire season. Managers knowingly playing ineligible players can, upon review, be suspended for up to the remainder of the season and the entire subsequent season.

All teams are required to pay half of their team fees by the originally scheduled start of the season. The remainder of the team fees are due at a date to be communicated by league officials. New teams may be granted extensions to these dates as needed. If either of these dates are missed, the team's next game will be immediately forfeited and any applicable funds will be credited to the effected teams. There are no minimum or maximum number of players on a team, so long as each player on the roster is officially sanctioned according to the criteria defined in the previous section.

The league will maintain a list of free agents that submit their info on the website. Manager access to this list is determined by league officials based on the current needs of teams in the league. Managers are free to use this list to fill their teams rosters as needed. Free Agents can be signed to any team at any time as long as they adhere to the player eligibility guidelines.

All players present at the field are required to be in the batting lineup. Batters cannot be removed or skipped, unless being removed due to injury or previous commitment. Batters who are present and are skipped over will be counted as an out.

Players arriving late are required to be added to the bottom of the batting line-up. No substitutions are allowed.

If a player is forced to leave a game due to injury or commitment, that spot is skipped and all batters move up accordingly with no penalty to the affected team. If a player is ejected and it leaves a team with 8 players, the 9th spot will be an out. If it leaves the team with 7 players, then the team forfeits the game.

All teams must have at least 8 players for an official game and may borrow from an opposing team with the opposing manager's consent, or may borrow a player from another team. If the teams 9th player arrives after the start of the game, the borrowed player reverts back to his team. If the borrowed player is from a different team he will be allowed to finish the game. Borrowed players must play outfield only. During tournament games the borrowed player is not to be added to the batting lineup. The team must take the 9th out. If the 9th player for that team arrives, the borrowed player can no longer play in the game.

A team choosing or forced to play the game with 8 players due to unavailability of sanctioned players must take an out in the 9th batters position. The opposing manager can nullify this rule if he chooses to do so, then the team with 8 players will not take an out in the 9th batting position.

In the event a team has fewer than 8 players, a forfeit will automatically be declared and a win awarded to the opposing team. Forfeits will be declared no later than 15 minutes after the intended game start time.

All players may be substituted defensively at anytime between innings without affecting the player's status in the batting line-up.

In the event a player quits, or is suspended from play with an active team during the season, all league fees will be forfeited. In the event a player is asked to leave a team at the request of the manager and/or the rest of the team, any refund of players fees will be made by the team, at the discretion of the team's manager.

All games, unless otherwise determined, will be 9 complete innings. In the event of a weather delay or inadequate lighting, a game will be considered a complete game at 5 innings. This applies to both regular season and tournament / play-off games.

All regular season games will be played with a 3 hour time limit. No new inning will start after 2 hours and 45 minutes. Any inning already in progress should be played to completion. In the event of a tie after 3 hours where no game is scheduled to follow, then the game should be continued to determine a winner. In the event of a tie after 3 hours where a game is scheduled to follow, the California rule will take effect starting after the first full overtime inning.

When the California rule is in effect, each teams begins their half of the inning with a runner at 2nd base and one out. If the game is still tied after 2 full innings of the California Rule in effect, a league official should determine if the game should be postponed or continued to resolution.

Regarding time limit / ties, all league tournament games will be played in full.

If there is a 10 run discrepancy after 7 innings or 15 after 6 the game will be ruled final at that point. This rule applies to both regular season and tournament games.

All games postponed or suspended will be rescheduled by the league if possible. Dedicated rainout dates will be added to the schedule at the end of the season. If unused, the tournament will be moved up accordingly.

Team managers are required to present a legible line-up with first and last names along with jersey numbers with all players listed at the plate meeting before each game.

Managers must report to the score keeper the change of a pitcher and the pitcher's name prior to the first pitch that pitcher throws. Must give first and last name and jersey number.

All teams are requested to maintain offensive and defensive scorebook for each game. Teams opting to not keep a scorebook will forfeit their ability to appeals any disputed calls or rulings. At a minimum, a per-inning box score should be kept by both teams to determine the final score. This box score is required for entry on the website.

Teams must declare prior to the start of the game which players will be eligible for courtesy runners throughout the duration of the game. Courtesy runners can be used for up to two of any combination of the following: the current active pitcher, the current active catcher or up to two specific players. If no declaration is made prior to the start of the game, it should be assumed that only the active pitcher and catcher are eligible. If active pitcher or catcher is chosen for courtesy runner eligibility, this does not apply for pitchers or catchers that are starting that position in the next inning. Only the current pitcher or catcher can receive a courtesy runner. If any specific players are selected for courtesy runner eligibility, they cannot be changed under any circumstance. Should any courtesy runner eligible player leave the game for any reason, including injury, their courtesy runner eligibility is forfeited for the remainder of the game. The courtesy runner must be the player who is not currently on base and has the longest number of positions to wait until they are up to bat again ( usually this is the last out ). Courtesy runners must be used as soon as the player has reached the farthest base, but before the pitcher has thrown the first pitch to the next batter.

A pitcher is allowed to hit only 4 batters in any 9 inning game, 3 batters in any 7 inning game. He must then be removed from the mound immediately after the 4th batter (3rd in a 7 inning game) is hit with a pitch. In the event it is determined by the umpire that a pitcher intentionally hit a batter, the pitcher shall automatically be removed from the game and a minimum of 1 game suspension shall follow the game in which the incident occurred. If the batter was intentionally hit in the head, neck or shoulder area, the suspension can be increased upon further review by a league official. If a pitcher is determined to have violated this rule for a second time, he shall be suspended from the league for the remainder of the season.

If a pitcher is removed from the game by the manager or decides on his own not to continue to pitch due to injury or fatigue etc. that pitcher can not return as a pitcher later in the game, but he may re-enter to play any other position.

All teams must have players dressed in full baseball uniforms: hats, jerseys, pants and baseball cleats. Each player's jersey must have a 6" minimum, screen-printed number on the back. Duplicate numbers are not allowed. All team jerseys must be of the same color and design. Team hats must all be of the same color. Pants should all be of similar style and similar color. Sponsor logos are allowed on team jerseys.

All players are required to use baseball cleats on the field. Metal or rubber spikes are required. Players are not allowed to play in tennis shoes or any other non-cleated shoe.

All teams must have their uniforms by the first game of the season. A grace period may be extended on hats and jerseys for new teams and/or newly activated players. Any player out of uniform is ineligible to play until the offending dress is resolved.

All batters and runners must have helmets on. Batters must wear a helmet that protects the ear facing the pitcher. Catchers must wear a full mask and skullcap/helmet. Anyone catching during pitcher's warm-ups must wear a catcher's mask.

Only NABA league baseballs are to be used in sanctioned games. Each team will receive 3.5 dozen NABA game balls during the regular season as part of their league fees. Should you run out of baseballs before the end of the season, please contact a league official. During regular season games, each team will be responsible for providing umpires with 3 new NABA game balls ( 6 total ). During tournaments, league officials will provide the NABA game balls to the umpires. During regular season games, dirty or otherwise exhausted baseballs should be replaced with any available used NABA baseballs. Damaged game balls should always be removed from play. During tournaments, exhausted game balls will be replaced with new balls. Game balls should be divided evenly amongst the teams at the end of the game to be used for practice. The winning team should get the larger of the two sets.

Solid Wood and Wood composite bats are required for regular season games and tournaments. No metal bats are allowed. Any player attempting to hit with an unapproved bat will be declared an out and be issued a warning.

Pitchers are not allowed to wear white or gray long sleeves, batting gloves or wristbands while on the field. A standard glove must be used as well.

All catchers must wear full protective gear including shin guards, chest protectors, full mask, skullcap/helmet and athletic cup / supporter.

The league has the right to suspend or expel any team member who abuses league rules, who does not exhibit good sportsmanship or who plays without regard to the safety of umpires, players, managers, officials, and fans.

Umpires have the sole discretion to expel any player or manager from the game. In the absence of league officials, umpires have the right to make judgement calls on any of the following policies.

If an umpire ejects a player or manager from a game, the league has the right to review the first occurrence which can result in a single or multi-game suspension depending on severity. Any subsequent ejections will result in a mandatory single or multi-game suspension.

The OABL adheres to a strict zero tolerance policy for alcoholic beverages, tobacco products and illegal drugs. Use of these are not permitted within 500 feet of any playing field or city park therein. This rule applies to all players, umpires, officials and spectators. Any individual abusing this policy will be suspended from the league and asked to leave the premises immediately. Players suspected of being under the influence of any of the aforementioned substances will be suspended or expelled from the league and asked to leave the premises immediately. League officials reserve the right to determine punishment for these offenses on a case-by-case basis.

Any manager or player throwing any equipment of any kind when not appropriate is subject to a verbal warning, ejection from the game or extended suspension.

Players, managers and spectators using profane language will be warned and/or suspended and asked to leave.

Players must not intentionally collide with any other player. If a runner intentionally collides with a fielder, the runner will be called out and may be expelled from the game. When a defensive player (e.g. catcher) has possession of the ball, is in the act of receiving the ball or is about to immediately receive the ball and will be able to make an apparent play on the base runner, that runner must slide either or give up their right to the base. They must avoid a collision by sliding, stopping or leaving the base line. The base runner need not slide if he is sure that he can legally and safely reach base. If the base runner decides not to slide and collides with the fielder, the runner will be called out. If the runner chooses not to slide and reaches the base without colliding with the fielder, but disrupts a throw in any way, from that fielder to an additional base, (that throw being an attempt to record an out at that additional base) the runner will be called out for interference. The runner attempting to reach or having reached that base that the throw was directed will also be called out due to the interference call against the first runner.

If a defensive player is not in possession of the ball; is not in the act of receiving the ball; or is not about to immediately receive the ball so that he is able to record an out (apparent play...at any base), he cannot block the base (e.g. home plate) or be in the base path so as to impede (obstruct) the base runners right to the base. Under such circumstances, the defensive shall be responsible to avoid any collision. If a collision does occur under these circumstances the runner will always be considered safe and the obstruction rule shall be enforced. The defensive player may be ejected from the game (if the action is intentional, he must be ejected), and will be suspended from league play if the obstruction is judged to be flagrant.

Fielders are not allowed to decoy a throw or catch. If a decoy throw or catch is detected, all runners shall be allowed to advance one base beyond the base held after all play stops. If the same fielder decoys twice in the same game, the fielder shall be expelled from the game. Decoying is referred to as a false catch or throw done in an attempt to get the runner to slide unnecessarily, where no strategic value is gained and no close play was apparent at the base or plate. This call is the umpire's discretion.

Use of unnecessary rough tactics during any play of the game against the body of any person will result in immediate suspension for a minimum of 3 games, up to the whole season.

Grievances may be filed by an individual player or by the manager of a team provided: that a grievance is formally submitted to the league in writing. The league shall adjudicate all such grievances and shall report any action taken.

All protests should be made to a league official within 24 hours of the end of the game in question. All protests will be reviewed and decided on by the League officials.

Any appeal of any action or ruling may be filed with the board by an individual player/manager of a team provided that the appeal is formally submitted in writing. ALL decisions by the league officials are final.