Caltrops

BTD6

BTDB2

Caltrops
General Information
Game	Bloons TD 6
Tower	Ninja Monkey
Unlocked at	500 XP
Cost	$380 (Easy) $450 (Medium) $485 (Hard) $540 (Impoppable)
Activated Ability	N/A
Targeting Options	First, Last, Close, Strong, Camo Priority, (Caltrops locked to Normal)
Camo Detection	Yes
Popology
Damage Type(s)
Sharp Camo affected Single Projectile Straight Attack Aggressive Seeking
Other(s)	Caltrops: Sharp Camo affected On Track Spike Straight Attack
Statistics
Damage	1 (shuriken) 1 (caltrops)
Pierce	2 (shuriken, excluding additional upgrades) 6 (caltrops, excluding additional upgrades)
Attack Speed	Moderately Fast (shuriken, every 0.62s, excluding additional upgrades) Slow (caltrops, every 3.9s, excluding additional upgrades)
Range	47
Status Effects	N/A
Tower Boosts	N/A
Income/Life Boosts	N/A
Path Upgrades
← Previous	Seeking Shuriken
← Previous	Seeking Shuriken
Current	Caltrops
Current	Caltrops
Next →	Flash Bomb
Next →	Flash Bomb
Path Info
Path	3
Path	3
Upgrade Tier	2
Upgrade Tier	2
Related upgrades
Spike Factory
[Source]

“	Throws out spiked caltrops onto the track nearby.	”
	~ In-game description

Caltrops is the second upgrade of Path 3 for the Ninja Monkey in Bloons TD 6. It gives the Ninja Monkey an additional attack that dispenses caltrops onto the ground every 3.9 seconds (every 2.73s with Ninja Discipline), similar to a Spike Factory. A caltrop can pop up to 6 Bloons before it is used up. Caltrops have a lifespan of 35 seconds or 1 round, whichever comes first. If given Distraction, the caltrops have a 10% chance to blow back bloons, compared to 15% via the main shuriken.

This upgrade costs $380 on Easy, $450 on Medium, $485 on Hard, and $540 on Impoppable.

Description

Overview

Caltrops Ninja with caltrops on the track

Ninja Monkey with Caltrops changes his suit from red to black and changes the four-pointed star emblem attached on his forehead plate to a larger silvery four-pointed star with blue at the tips.

By upgrading into the Caltrops upgrade, the Ninja Monkey now adds a caltrops attack. Each caltrop can pop up to 6 bloons with moderate production speed, every 3.9s at base and decreased cooldown to every 2.73s with 1-0-2 crosspath. Caltrops last for 35s or 1 round, whichever comes first. The caltrops attack is separate from the ordinary shuriken attack.

Targeting Priorities

Caltrops targets bloons using the standard targeting priorities. Its main shuriken attack shoots straight movement projectiles.

• First: Targets the first bloon visible within its range.
• Last: Targets the last bloon visible within its range.
• Close: Targets the closest bloon visible within its range.
• Strong: Targets the strongest bloon visible within its range.

Caltrops are locked on Normal targeting priority, which dispenses the caltrops onto nearby bloon track in a semi-sporadical behavior.

All Ninja Monkeys can access Camo Prioritization. While Camo Prioritization is active, it allows all its attacks to prioritize Camo Bloons over other types.

Full Popology

Statistics

Updated as of Version 44.2

Base stats

• Shuriken:
  • Projectile, sharp type, camo detection, 47 range, 0.62s attack cooldown, 1 damage, 2 pierce, aggressive seeking.
• Caltrops:
  • Projectile, sharp type, camo detection, detects and deploys on nearby track, 47 range, 3.9s attack cooldown, 1 damage, 6 pierce. Lifespan of 35s.

Crosspathing interactions

• 1-0-2: Shuriken attack cooldown reduced from 0.62s to 0.434s, Caltrops attack cooldown reduced from 3.9s to 2.73s,
• 2-0-2: Shuriken pierce increased from 2 to 4
• 0-1-2:
  • Shuriken applies Blowback (non-Ceramics: 100-150 units, Ceramics: 50-75 units) at 15% chance
  • Caltrops applies Blowback (non-Ceramics: 100-150 units, Ceramics: 50-75 units) at 10% chance
• 0-2-2: Shuriken and Caltrops can decamo bloons that they damage.

Monkey Knowledge interactions

• Lingering Magic: Projectiles fired from all Magic Monkeys (except Alchemists) have longer lifespan.
• Hot Magic: All Magic type towers can pop Frozen Bloons.
• Monkey Education: All Monkeys XP earn rate increased by 8%.
• Better Sell Deals: All Monkeys sell for 5% more. Increases sell potency from 70% to 75%.
• Veteran Monkey Training: All Monkeys reload time reduced by 3%.

Attack Interactions

See also: Attack Interactions/Bloons TD 6/Magic

Updated as of Version 44.2

Base attack(s)

• Shuriken:
  • Sharp
  • Camo Detection
  • Single Projectile
  • Straight Attack
  • Aggressive Seeking
• Caltrops:
  • Sharp
  • Camo Detection
  • Single Projectile
  • Straight Attack
  • On-Track
  • Spike (lifespan: 35s or 1 round)

Costs

Updated as of Version 44.0. Listed prices exclude external buffs, any sacrifices, and Monkey Knowledge.

[Module | Data]	Purchase				Sell
Costs	Easy	Medium	Hard	Impoppable	Easy	Medium	Hard	Impoppable
Upgrade (X-X-2)	$380	$450	$485	$540	-
Total (0-0-2)	$975	$1,150	$1,240	$1,380	$683	$805	$868	$966
Crosspath (1-0-2)	$1,270	$1,500	$1,620	$1,800	$889	$1,050	$1,134	$1,260
Crosspath (2-0-2)	$1,565	$1,850	$2,000	$2,220	$1,096	$1,295	$1,400	$1,554
Crosspath (0-1-2)	$1,185	$1,400	$1,510	$1,680	$830	$980	$1,057	$1,176
Crosspath (0-2-2)	$1,525	$1,800	$1,940	$2,160	$1,068	$1,260	$1,358	$1,512

This upgrade's prices (or included crosspath's prices) are affected by the following MK: Better Sell Deals

Strategy

Summary

Purchasing the Caltrops upgrade adds secondary Caltrop throw acting very similar to Spike Factory. Because of the potential to stockpile spikes, it is a very useful low-cost option for countering Camo Bloons in earlier rounds, as well as adding up extra overall damage in the early mid-game. Contrary to popular belief, Caltrops is highly beneficial with Alchemist buffs, as spike piles will always retain buffs provided that they are dispensed while the original tower gained the buffs.

This upgrade basically allows Ninja to hybridize Spike Factory with its own primary attacks. The caltrop attack can benefit from Ninja Discipline to dispense caltrops at a faster rate, but with any other upgrade it generally works independently as a crosspath otherwise.

Tips

• Caltrops that are dispensed while under influence of Stronger Stimulant will give such Caltrops +3 pierce and +1 damage, giving each Caltrops a total of 9 pierce and 2 damage.
• Note that Caltrops consume one unit of Acidic Mixture Dip or Berserker Brew/Stronger Stimulant.
  • Unlike popular belief, Caltrops does not actually slow down the Ninja Monkey's main shuriken attacks, as the caltrops throwing animation does not at all interfere with the rate of shuriken throwing. This makes the Caltrops upgrade not a bad choice for some extra popping power.
  • Caltrops that are on the track will not wear out its Acidic Mixture Dip if the original tower's Acidic Mixture Dip wears out. In fact, Caltrops that were affected by Acidic Mixture Dip will retain their bonuses until consumed or destroyed.
• Caltrops Ninjas nearby Level 11+ Obyn will become much more powerful, which allows them to be deploying extra sharp caltrops with +2 pierce. Additionally, Shinobi Tactics Ninjas in huge groups will cause nearby Caltrops Ninjas to produce massive caltrop piles, which in turn deal massive overall stockpiled on-track damage, especially so due to the massively increased attack speed and pierce of every attack.
• Although Grandmaster Ninja doesn't improve the stats of the Caltrops aside from the Ninja Discipline speed benefit, it is still worth giving Grandmaster Ninja this crosspath to slightly increase its single-target damage.
• Unlike Spike Factories, Caltrops cannot ignore Line of Sight, which means the Ninja Monkey needs to directly see bloon track in order to dispense any caltrops around any visible bloon track.
• Caltrops have a unique role in Boss Bloon Events, especially on weeks where Spike Factories are banned. Large groups of Shinobi Ninjas can generate massive amounts of caltrops, and this can take advantage of the three second time that it takes the Boss to spawn in. This can deal massive damage when combined with buffs like Support Sun Temples and debuffs like Cripple MOAB, Glue Storm, and Super Brittle, This is especially notable for Lych, as the Ninjas can take advantage of the time Lych is invulnerable to set more caltrops.

Version History

Balance Changes

Small rework to Caltrops was likely done to reduce wearing off Alch buff consumption via the caltrop attacks, although it can be seen as a nerf overall, since Caltrops do not even wear off Alch buffs fast enough anyway.

9.0

• Caltrops with Grandmaster Ninja now has more pierce (3 → 5)

12.0

• Caltrops attack speed decreased by 100% (every 2.2s → 4.4s).
• Caltrops pierce increased by 100% (3 → 6). Does not affect Grandmaster Ninja's caltrops (5).

28.0

“	As ninja is the 'Camo Specialist' and has been since inception, it is the only tower that will unlock Camo Prioritization on the base tower. [...]	”
	~ Ninja Kiwi

• Affected by base Ninja Monkey, by gaining natural Camo Prioritization target option

29.0

• Caltrops now can distract bloons with Distraction

36.0

“	Ironing out Caltrop inconsistency & power a little on top and bottom T5s, but also as frequently unused caltrops clutter up the screen and cause extra lag we want to balance out their lifespan to reduce the number always on screen and make them no longer last longer than the base Spike Factory. [...]	”
	~ Ninja Kiwi

• 5-0-2 Caltrops pierce increased from 5 → 6
• Caltrops lifespan reduced from 70s → 35s

38.0

• Affected by Seeking Shuriken base range increase

40.0

“	For an early game Distraction improvement the consistency of blowbacks is being averaged out more with increased minimum distance but reduced maximum, in many cases there would not actually be 250 units of track length in front of defenses to be blown back across anyway so the overall average distance is slightly lower. More at the mid to endgame we are also weakening distraction distance against Ceramics specifically as by this point Ninja have stacked so much speed and projectiles the consistency doesn’t matter anymore. Finally, distraction values for secondary projectiles are being modified, as Distraction chance as it has existed was never balanced around more than the main attack	”
	~ Ninja Kiwi

• 0-1-2 Caltrops Distraction chance of caltrops reduced (15% → 10%)

43.0

“	While a great early game option, Ninja generally struggles with dominant crosspathing choices and also has relatively poor base tower value. Without going into every single change, T3s onward remain relatively unchanged with a lot of prices below T3 being moved around from less favorable crosspaths into better/higher tier upgrades. [...]	”
	~ Ninja Kiwi

• Caltrops cost increased from $400 to $450
  • Total price adjustment is $0 due to base Ninja (-$100) and Seeking Shuriken (+$50)
• Caltrops base shuriken attack cooldown decreased from 0.7s to 0.62s. Does not affect 1-0-2 (0.434s).
• Caltrops attack cooldown of caltrops reduced from 4.4s to 3.9s
• 1-0-2 Caltrops attack cooldown of caltrops increased from 2.728s to 2.73s

Gallery

Crosspathing (Top: Path 1, Bottom: Path 2)

Lots of caltrops on the map by a 2-0-2 Ninja

Stacks of caltrops by a 1-0-2 Ninja

Two 0-0-2 Ninjas with Caltrops upgrade

Official artwork

Upgrade portrait

Upgrade icon

Instamonkey icon

Trivia

• The Caltrops upgrade redesign in Version 12.0 indirectly nerfed the Grandmaster Ninja + Permanent Brew 2TC combo, as each caltrop from the 5-0-2 Grandmaster Ninja overall does less DPS than normal. In particular, there are fewer numbers of caltrops spawned at once, thus benefiting less from the +2 pierce per projectile from the Grandmaster Ninja and +3 pierce per projectile from Permanent Brew. This has made the combo impossible to do as of said version.
• When Grandmaster Ninja was crosspathed with Caltrops after the 9.0 balance changes, the +2 pierce bonus for the shurikens also applies to the caltrops, making them have 5 pierce between Version 9.0 and 11.0, but 8 pierce each in Version 12.0. This provided more value with damage buffs.
  • This has since changed after the rework of Grandmaster Ninja, thereby leaving the Caltrops pierce at 5 instead of 6, nerfing the Caltrops attack.
• The upgrade icon resembles the Long Life Spikes upgrade for the Spike Factory.
• Early on in the game's history, there were rumors that caltrops was actually a downgrade because it would supposedly make its main attack fire slower. This was never true, and it stemmed from Bloons Adventure Time TD where Sai's Tetsubishi attack would occasionally interrupt her regular attack. This has since been fixed there in the 1.4.1 update. Caltrops does, however, consume alchemist buff shots, but there has never been any evidence that this has made the Ninja Monkey worse overall.