In baseball, a fair ball is a batted ball that entitles the batter to attempt to reach first base. In order for a batted ball to be fair, it must be hit in such a way that it:

• settles on fair ground between home and first base, or between home and third base; or
• is on or over fair territory when bounding past first or third base; or
• touches first, second, or third base (which by rule are in fair territory); or
• touches the person of an umpire or player while the ball is on or over fair territory (unless it touches the batter in the batter's box, or bounces off the ground and immediately hits the bat); or
• passes out of the playing field in flight while over fair territory, or touches any part of the foul pole, including any attached screen, while in flight; or
• strikes any object for which the specific ballpark's ground rules specify that a batted ball striking that object is a fair ball (e.g., a roof if present); or
• lands for the first time in fair territory in the outfield.