Added twin gun doubles attack speed.
~ Description from Bloons TD 5
Added twin gun doubles attack speed. Enhances Ballistic Missile and Bloontonium Reactor.
~ BTD6 description

The Monkey Sub with twin guns.


BTD6 official artwork

Twin Guns is the first upgrade on the second path for the Monkey Sub in BTD5 and the third path in BTD6. It adds a second gun to the sub, which enables it to fire twice as fast. This can be useful when used in combination with Barbed Darts because the sub now essentially has 6x (5x in BTD6) the popping power of an unupgraded Monkey Sub (1 pierce in BTD5, 2 pierce in BTD6).


Easy: $380, Medium: $450, Hard: $485, Impoppable: $540


  • This upgrade is usually used as a stepping stone to the next upgrade, Airburst Darts.
  • This upgrade is useful for early-game due to its relatively fast attack speed. In BTD6, this upgrade is far more useful due to each dart having 2 pierce each instead of 1, and combined with the homing pattern of Monkey Subs it makes the 0-0-1 Sub a powerful early-game tower.

Version History (BTD6)Edit


Buff Twin Guns now increases attack speed of Submerge and Support, Bloontonium Reactor, and Ballistic Missile.


Nerf Twin Guns now grants less bonus attack speed for Upper Path 2's ballistic missiles (see Ballistic Missile or Pre-Emptive Strike for more specific info)



  • The old description for Twin Guns used to be the same as in BTD5, but has since changed in Version 18.0 due to a buff to the interactions with Bloontonium Reactor and Ballistic Missile.
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