All Primary Monkeys in radius get tier 1 upgrades for free.
~ BTD6 description

Primary Mentoring is the fourth upgrade of Path 1 for the Monkey Village in BTD6. It allows all Primary towers within its radius to be granted free tier 1 upgrades. As of Version 17.0, it also grants Primary Monkeys with +5 range and reduces their ability cooldowns by 10%. It costs $2125 on Easy, $2,500 on Medium, $2700 on Hard, and $3000 on Impoppable.


  • For the free Tier-1 upgrades, Primary Mentoring is best used with Bomb Shooters, as their Tier-1 upgrades collectively are the most expensive of their kind.
    • The two most expensive Tier-1 Bomb Shooter upgrades are Bigger Bombs ($400 on Medium) and Faster Reload ($250 on Medium). However, the key value of the discount portion of the Primary Mentoring upgrade is when spamming in 2-0-4 Recursive Clusters, thereby saving up to $600 on Medium ($400 + $200, Medium prices) per Bomb Shooter.
  • Primary Mentoring works well with Primary Monkeys that have abilities, such as Super Monkey Fan Club, Super Maelstrom and Turbo Charge.
  • Primary Mentoring's +5 range bonus is additive on top of the multiplicative +10% range bonus from Primary Training. As such, this particular bonus benefits the most for Ice Monkeys and Tack Shooters.

Version HistoryEdit

  • Buff Primary Mentoring now reduces ability cooldowns of primary monkeys in radius by 10%
  • Buff Primary Mentoring now adds +5 range to primary towers in range.



  • The most expensive upgrade that can be purchased for free with Primary Mentoring is the Bigger Bombs upgrade from the Bomb Shooter, saving $400 on Medium each.
    • The most expensive combination of upgrades that become free by the Primary Mentoring benefit is the Bomb Shooter with Bigger Bombs and Faster Reload, totaling a saving of $650 on Medium each.
  • Even though Primary Mentoring was buffed in Version 17.0, the description was not changed to accommodate the bonus benefits.
  • In Version 17.0, there was a bug where upgrading to Primary Expertise did not grant the special Primary Mentoring bonuses to nearby Primary Monkeys. This was fixed as of Version 17.1.

Start a Discussion Discussions about Primary Mentoring

  • New Primary Mentoring description?

    4 messages
    • Indeed, but every description of the upgrade must quote-on-quote match the description used by the official game, even if the description does ...
    • Qwertyxp2000 the second wrote:Because of the new buffs to Primary Mentoring, I think the description should now be "All Primary Monkeys...
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