In
baseball, a
foul ball (often shortened to '
foul') is any
ball hit by a
batter into
foul territory -- that is,
out of bounds (left of the left
foul line, right of the right
foul line, or behind
home plate --
hitting a
ball over the far wall of the
playing field is, of course, a
home run). This includes
balls which bounce off the
pitcher's rubber and enter
foul territory, as well as
balls which touch a person (
player or
umpire or an 'object foreign to the natural ground' while in
foul territory.
1
Foul balls are considered strikes, but a batter can not strike out on a foul ball. If a batter has two strikes and hits a foul ball, the count remains unchanged and the pitcher continues to pitch to that batter.
Should a fielder catch a foul ball before it hits the ground, the batter is out -- this is called 'fouling out'.
1 Official Rules of
Baseball 2000 Edition