Increases attack speed and pierce of nearby Ninjas. Stacks 20 times.
~ BTD6 Description
Shinobi Tactics (commonly shortened to Shinobi) is the third upgrade of Path 2 for the Ninja Monkey in BTD6. It allows itself and all Ninjas around its radius to increase attack speed by 8.7% (multiplicative, multiplies cooldown by 0.92x each time) and pierce by 8% (additive). This upgrade's buff can stack up to 20 times, for up to +430% attack speed and +160% pierce.
Shinobi Tactics can be used to improve the overall performance of all nearby Ninja Monkeys within range. Placing a considerable number of them can greatly empower higher level Ninja Monkeys, specifically Grandmaster Ninja and Master Bomber. Themselves also provide considerably good Distraction and Counter-Espionage effects if placed within densely packed groups of Shinobi Tactics.
In a similar way to placing nearby Monkey Villages, space consideration is very important while applying support via Shinobi Tactics, although special attention should be considered with nearby buffing Alchemists (specifically Stronger Stimulant). For Stronger Stimulants in particular, place the buffing Alchemist as close to the powerful Ninja(s) as much as possible, while keeping them as far from the Shinobi Tactics as possible, so as the buffing Alchemist won't waste its potential on single neighboring Shinobi Tactics Ninjas.
Usually, it is best to leave Shinobi Tactics as 0-3-0, unless it is to increase Shinobi Tactics coverage range, in which 1-3-0 should be enough range to reach nearby high-level Ninjas for that significant attack speed boost. 2-3-0 is not necessary unless it's to improve its main attack.
Groups of 0-3-2 can be used to apply lots of caltrops via the Caltrops upgrade in addition to seeking bloons and apply Distraction with their main shuriken attacks. While Caltrops may be better against single-target bloons, groups of 2-3-0 are superior at handling normal bloons in the late-game, though 0-3-2 still comes with stockpilable Distraction.
If there are multiple Shinobi Tactics around a Bloonjitsu or Grandmaster Ninja, those high-level ninjas will not necessarily require crosspathing with Path 2, as Shinobi Tactics Ninjas already come with decently reliable Distraction and Counter-Espionage attacks, particularly when in very large groups.
Adding Shinobis for pierce buffs will greatly improve the shurikens of every Ninja in range; adding enough Shinobis nearby each other will allow them to produce excellent Distraction blowback to massive amounts of Ceramics, particularly on Rounds 81+.
To clarify the mechanics of pierce buffs with partial pierce (e.g. 1.5 pierce), partial pierce will be treated as "every 1/X shots, pierce increased to Y + 1", where X is the decimal part and Y is the integer part. So for example, 1.5 pierce would be treated as "every 2nd shot, pierce increased to 2" Link.
One 0-3-0 Shinobi Tactics Ninja costs $2390 on Hard Difficulty. Having 20 of them costs $47,800 on Hard Difficulty. This is especially important in CHIMPS Mode, as it is often unwise to overspend on unnecessary Shinobi Tactics Ninjas that do not improve Grandmaster Ninja or Master Bomber.
Shinobi buffs table
Number of Shinobi Ninjas
Attack Speed Increase (approx.)
Number of Shinobi Ninjas
Shinobi Tactics now also provide a pierce boost to nearby Ninjas, which makes a significant difference versus dense rounds. It was likely also done to improve simple Shinobi spam in itself.
Shinobi Tactics now also applies its 8% attack rate buff to pierce as well (Up to a 160% max increase).
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. [...]
Shinobi Tactics and Trade Empire can stack its buffs the most amount of times, that being 20 times.
This upgrade is similar to Poplust, since they both affect their respective monkeys with an attack speed and pierce buff that stacks.
However, Poplust cannot buff itself and stacks only 5 times.
In Version 11.0, the old description was changed from "Increases attack speed of all ninjas nearby - more Shinobi means more attack speed." to the new description, due to both the need to highlight the maximum stacking limit and to accommodate the inclusion of the new pierce buff.