All Primary Monkeys in radius get tier 1 AND 2 upgrades for free. Gains Mega Ballista attack.
~ BTD6 descrpition

Primary Expertise is the fifth-tier upgrade of the Monkey Village in Path 1 of BTD6. It allows all Tier-1 and Tier-2 upgrades for Primary Monkeys within its radius to be purchased for free, increases the pierce bonus to Primary Monkeys to +4 instead of +1, and gives the tower a powerful "Mega Ballista" attack. The attack fires a magical circular blade which strikes at any range and occasionally adjusts its direction mid-flight to hit more bloons, similar to Glaive Ricochet. Each blade pops 10 layers per hit and pierce through up to 100 regular bloons or 10 MOAB-class Bloons, while it deals 200 damage to Ceramics and M.O.A.B. Class Bloons. It costs $21250 on Easy, $25000 on Medium, $27000 on Hard, and $30000 on Impoppable.


The best investment for the free upgrades is used in conjunction with many Bomb Shooter or Glue Gunners with Glue Splatter, as they have quite pricy upgrades. In fact, the most recommended combination to make the best use of the Primary Expertise discount aspect is to spam in Bomb Shooters and Glue Gunners that are designed for all aspects of the defense, while they also get supported by Primary Training.

As for the main attack of the Primary Expertise, it deals 10 layers of damage to bloons (200 damage to Ceramic and M.O.A.B. Class bloons) with an infinite-ranged homing blade that can travel through solid objects.

Version HistoryEdit


Buff Alchemist potions can now target Primary Expertise. Does not temporarily boosts range at all, however.


Buff Primary Expertise now increases pierce of Primary Monkeys even more (2 --> 4)

Buff Primary Expertise's ballista attack increased damage to MOAB-class (100 --> 200) and now deals more damage to Ceramics (10 --> 200)



  • The most expensive upgrade that can become free with this tower is the Glue Splatter, saving up to $2,160 on Impoppable for the upgrade alone.
  • The Mega Ballista attack is similar to the High Energy Beacon's lasers from BTD5.
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