Bloons Wiki
Bloons Wiki

Purchased price of first Spike Factory each game is $150 less.
~ In-game description

First Last Line of Defense is a Support Monkey Knowledge point in Bloons TD 6, added in Version 22.0. It allows the first Spike Factory placed on the map to cost $150 less regardless of game modes. It requires One More Spike before unlocking this upgrade.


The following are prices for the Spike Factory with and without the effect of First Last Line of Defense:

Tower Easy Medium Hard Impoppable
Spike Factory, first $700 $850 $930 $1,050
Spike Factory, second and later $850 $1,000 $1,080 $1,200

This discount applies to the first and only the first placed Spike Factory. Even if the player sells the first placed Spike Factory, the next "first" placed tower will be at base price.



A simple discount for the first Spike Factory allows it to be afforded easier.


  • In combination with More Cash, this MK allows a base Spike Factory to be usable as a starting tower on Easy or Medium.

Version History[]

  • Added First Last Line of Defense



  • First Last Line of Defense is the first base tower discount-related MK to be released after initial release.
  • The word pun "First Last Line of Defense" likely refers to the fact that Spike Factories are mostly used near the exits to pop any Bloons that escape other towers, making them effectively the last line of defense. (The in-game description of the Spike Factory also explicitly calls it as such.) Since it applies only to the first Spike Factory that is bought, the name means it reduces the base cost of the first "last line of defense".