Monkey Knowledge
Cheaper Doubles
Cheaper Doubles in BTD6: the Ninja Monkey's Double Shot upgrade costs $100 less on every difficulty. When it helps and what it unlocks.
Ninja Double Shot cost reduced by 100.
Guide
Cheaper Doubles is a second-row Magic knowledge that lowers the price of the Ninja Monkey's Double Shot upgrade (tier 3 top path) by a flat $100. It requires SUPER Range, costs one Knowledge Point and no Monkey Money, and unlocks Diversion Tactics.
The discount is applied after the difficulty multiplier, so it is $100 on every difficulty. Version 57 fixed an issue where flat discounts like this one were calculated incorrectly outside Medium.
How it changes the game
Double Shot (3-x-x Ninja Monkey) makes the Ninja throw two shurikens per attack and is the step to Bloonjitsu and Grandmaster Ninja. It is a popular mid-game tower because Ninjas have camo detection built in. A $100 saving:
- Mid-game timing: you reach Double Shot slightly sooner, which helps on rounds where camo bloons and dense groups start to mix.
- Saving toward Bloonjitsu: every dollar saved at tier 3 goes into the tier 4 save-up.
- Multiple Ninjas: strategies using several top-path Ninjas, for example with Shinobi Tactics support, save $100 on each.
Only the Double Shot upgrade is discounted. Lower tiers, Bloonjitsu, Grandmaster Ninja and the other Ninja paths cost the same. The tower's stats do not change.
Is it worth it?
Priority: situational. For Ninja players it is a small, steady saving; for everyone else it is a cheap step on the way to stronger knowledge. Below it, Diversion Tactics leads to Deadly Tranquility, which adds an extra shuriken to Bloonjitsu, Grandmaster Ninja and Ascended Shadow, and then to Tiny Tornadoes.
Compared with its sibling Heavy Knockback, which leads toward Strike Down The False and There Can Be Only One, Cheaper Doubles is the better route for Ninja players and the other is better for Super Monkey players. Both cost only one point, so they also help you reach the 4-point threshold for Magic row three.
Where it works
Cheaper Doubles is active wherever Monkey Knowledge is enabled, on every difficulty, including Magic Monkeys Only, Impoppable, Races and Boss Events. It is disabled in CHIMPS, where Double Shot is full price, and in challenges that switch knowledge off.
Frequently asked questions
What does Cheaper Doubles do?
It reduces the price of the Ninja Monkey's Double Shot upgrade by $100.
Is the discount the same on every difficulty?
Yes. It is a flat $100 applied after the difficulty price change.
Does Cheaper Doubles affect the Monkey Buccaneer's Double Shot?
No. Only the Ninja Monkey's Double Shot upgrade is discounted.
What does Cheaper Doubles unlock?
Diversion Tactics, which leads to Deadly Tranquility.
Is Cheaper Doubles worth it?
Yes as a cheap point on the way to Deadly Tranquility; the discount itself is minor.

