Bouncing Betty

A Bouncing Betty is a land mine featured in Call of Duty 3, Call of Duty: World at War, Call of Duty: Black Ops, Call of Duty: Modern Warfare 2 (singleplayer) and Call of Duty: Modern Warfare 3.

Multiplayer
In World at War, it is unlocked at multiplayer level 24. It is given to players using the Bouncing Betty X2 perk. Bouncing Betties are not encountered in the campaign.

Bouncing Betties are considered more effective than claymores (their equivalent in the more modern era) for a number of reasons. They explode through the full 360 degrees and are easier to conceal because they are smaller and have no red lasers. They are also "dug in", even on hard surfaces. Only a glowing yellow rod will appear. Players will often attempt to shoot the glowing rod, which does no damage - the base must be hit.

Bouncing Betties, once placed, remain until triggered, destroyed, or the player who sets them respawns. They are triggered by the proximity of enemy players - even in hardcore game modes, friendly players will not set them off by proximity (although they will damage friendly players in hardcore should they explode). They can 'see' through walls, which can be a disadvantage as an enemy safe on the other side of a wall may unwittingly trigger them. Bouncing Betties can be destroyed by damaging the base with any gun or explosive.

Bouncing Betties can be particularly useful in area denial, specifically to prevent flanking or to protect an objective. In Search and Destroy they remain even after the player who set them has died, making them very useful for defending a bomb site before (defense) or after the bomb is planted (offense). A good strategy to use while fielding this weapon is to put it just inside the door on right or left, this way the enemy cannot see it unless they have the Bomb Squad perk.

Zombies
Bouncing Betties are also found in the Zombies maps Verrückt, Shi No Numa, and Der Riese and can be bought off the wall for 1000 points. Betties come in handy in the higher levels due to their high power, and they are often used to help a group of players camp, as players that are reloading can use them to protect themselves until the reload is complete. In higher rounds, Betties will not kill Hellhounds. They are restored after every round at a rate of 2, like grenades. They are also available in the Black Ops versions of the maps, functioning just like their World at War counterparts.

Call of Duty: Modern Warfare 2
Bouncing Betties appear in the MW2's singleplayer. But they aren't named "Bouncing Betties". They appear in the mission Loose Ends.

Call of Duty: Black Ops
Bouncing Betties are only available in Black Ops in the remastered Verruckt, Shi No Numa, and Der Reise, available by purchasing the limited edition or through the Rezurrection DLC. They cost the same and function just like their World at War counterparts.

Call of Duty: Modern Warfare 3
Bouncing Betties return in Modern Warfare 3 as equipment in multiplayer. The Bouncing Betty is thrown, and will beep, and flash a green light, presumbably to friendlies. It's the same model than the MW2's Bouncing Betties.

Trivia

 * It is possible to get the Bouncing Betties on the iPhone version of Nacht Der Untoten.
 * Bouncing Betties triggered at the end of a round on Search and Destroy result in the whole match freezing for one or two seconds.
 * In First Person, the player holds the Bouncing Betty with one hand; in Third Person, the player holds it with both hands.
 * On the Wii version, when keeping a ready-to-plant Bouncing Betty in hands and moving, the player's hand model will be deformed depending on the player's move direction.