In baseball, when the ball is dead, no runners may advance beyond bases they are entitled to, and no runners may be put out. The ball becomes dead when:

• A batter is touched by a pitch or a batted ball
• The plate umpire hinders a catcher's throw attempt
• A ball is illegally batted, such as when a batter hits the ball while outside of the batter's box
• A foul ball is not caught
• A fair ball touches a runner or an umpire on fair territory before it touches an infielder (including the pitcher)
• A fair ball touches an umpire before it has passed an infielder other than the pitcher
• A live ball lodges in the umpire's or catcher's equipment or in a fence or in another object on the field
• A foul tip hits the umpire and is caught by a fielder (probably the catcher) on the rebound
• Any legal pitch touches a runner trying to score
• A live ball passes out of the playing field
• A runner or fan commits interference
• The defense leaves the field after the game ends
• An umpire calls "Time." Umpires typically call "time" after being asked to do so by a participant. An umpire in chief will also call "Time" when:
  • Weather, darkness or similar conditions make play impossible or dangerous
  • Light failure makes it difficult or impossible for the umpires to follow the play
  • An accident incapacitates a player or an umpire
  • The umpire wishes to examine the ball, to consult with either manager, or for any similar cause.
  • An umpire orders a player or any other person removed from the playing field.
  • A balk or obstruction is committed and immediate ensuing play ends
  • The catcher interferes with the batter before the time of pitch

The ball does not automatically become dead after playing action ends.

After a dead ball, the ball becomes alive again when the pitcher stands on the pitcher's plate ready to pitch, the batter, catcher and umpire are ready, and the umpire calls or signals "Play."