Foul

In baseball (not a soccer or basketball foul), when a ball is hit out of play past either the first base or third base line. Even if a ball is dropped by a player in foul territory, it still counts as a foul, while any ball cut becomes an out.

Foul balls are also lightning rods for fan interference calls. If a fan reaches out into the field of play and interferes with a catchable foul ball, an out is ruled. If that happens in the stands, the player isn't ruled to have right to the ball, and it's simply a foul ball.

Any number of foul balls can be hit without adding any strikes to a batter.