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Holds a trusty nail-gun to pop the Bloons. Can upgrade to create its own nail-shooting sentry turrets.
~ In-game description

The Engineer Monkey is a Support-class tower in Bloons TD Battles 2.

Engineer Monkey wields a nailgun that shoots nails at bloons. He shoots one nail every 0.70s, and each nail pierces up to 3 bloons. Engineer starts with a base range of 40. The main power of the Engineer comes from contraptions and other applications of mechanical engineering. He can be upgraded to produce sentries of various types, Cleansing Foam, and Bloon Traps. He can also be upgraded to boost other towers by the use of a power wrench, amplifying the attack speed of its targets with Overclock.

The base price for Engineer Monkey is $400. It is unlocked by spending Monkey Money1000, unlocking all upgrades up to Tier 4, plus another Monkey Money1500 to unlock all its Tier 5 upgrades.

Description[]

The Engineer Monkey features a yellow hard hat as it did back as Monkey Engineer in BTD5. Its nailgun is smaller than its BTD5 counterpart, and is colored yellow. Because of the nailgun's smaller size, it only needs to hold it with just its right hand instead of with both hands.

Path 1 focuses on damage and deployment of Sentries. It allows Engineer to build secondary towers as decent backup defense, with further upgrades increasing their effectivity. Sentry Expert allows the engineer to build specialized sentries to add versatile support against certain bloons. Its 5th tier Sentry Champion allows building of very powerful unstable sentries that before disappearing explode, dealing huge damage to nearby bloons.

Path 2 focuses on support. Larger service area allows the engineer to shoot from a longer range, while Deconstruction improves MOAB and Fortified damage. Cleansing Foam removes Camo and Regrow properties off bloons, Overclock allows the engineer to temporarily increase attack speed of targeted tower by 66%. (Duration varies by tier of tower) (For banana farms it increases income and for villages it increases influence radius). Ultraboost adds permanent 13.33% to overclocked tower that stacks up to 5x for maximum of 66% permanent increase.

Path 3 focuses on a combination between stalling and cleanup. Its Pin upgrade allows the engineer to pin any non-moab class bloon except for ceramic and lead, temporarily stopping it from progressing for short time. Bloon Trap allows any non-moab class bloon to be trapped until it is full which can be manually collected (with some bonus cash). Its 5th tier |XXXL Bloon Trap significantly increases the capacity and can also trap Moab class bloons (excluding B.A.D).

The Engineer Monkey Paragon, the Master Builder, is the final upgrade for all three paths. It incorporates most features of the Engineer, with notable exceptions including foam and traps.

Target Priorities[]

The base Engineer Monkey uses the standard target priorities: First, Last, Close, Strong. Most of the Engineer's alternate attacks do not integrate its own target priority.

  • 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.

All of the Engineer Monkey's alternate attacks have a different set of target priorities:

  • Sentry spawning tends to follow based on the Engineer's perception of where bloons will most likely move around. Hence, sentry spawning depends slightly on RNG but is not entirely RNG-based. Sentry spawns also attempt to only target unoccupied areas of the map. If there are many towers within range of the Engineer blocking potential land spots, the Engineer will spawn sentries between the space of other towers.
  • Sentries themselves start with the target priority of the main Engineer at the time of spawning. Individual sentries must have their target priority changed manually from their current target priority.
  • Cleansing Foam location is able to be chosen by the player. Foam is placed on Close by default.
  • Overclock and Ultraboost abilities require user input to pick the tower to boost.
  • Bloon Traps and XXXL Traps are always placed on Close regardless of the Engineer's own target priority, unless Larger Service Area is bought. Then the player may choose a place in range of the engineer to place it.

Upgrades[]

Path 1[]

SentryGunUpgradeIcon
Sentry Gun
COST: $400
UNLOCK: Requires Engineer Monkey

Description: Creates temporary sentry guns and deploys them nearby.
Effect: Produces temporary sentry guns onto nearby land at a fixed production rate. Sentry Guns pop up to 2 bloons per shot, lasts for up to 25 seconds before disappearing, and can be improved with crosspathing.
FasterEngineeringUpgradeIcon
Faster Engineering
COST: $350
UNLOCK: Requires Engineer Monkey

Description: Increased efficiency allows the Engineer to produce sentries, bloon traps, and cleansing foam more often.
Effect: Produces sentries, traps, and foam +66% faster (0.60x attack cooldown).
SprocketsUpgradeIcon
Sprockets
COST: $500
UNLOCK: Requires Engineer Monkey

Description: Increases sentry gun and Engineer attack speed.
Effect: Nailgun and newly deployed sentry guns attack +66% faster (0.60x attack cooldown).
SentryExpertUpgradeIcon
Sentry Expert
COST: $2,800
UNLOCK: Requires Engineer Monkey

Description: Sentries deploy with different damage types based on your need.
Effect: Replaces all new sentries with four specialized sentries: Crushing, Boom, Cold, and Energy. Adjusts deployment of these four sentry types depending on bloons on the screen.
SentryParagonUpgradeIcon
Sentry Champion
COST: $32,000
UNLOCK: Monkey Money1,500 (T5 Engineer Unlocks)

Description: Creates super-powerful but highly unstable sentries.
Effect: Replaces all new sentries with powerful plasma sentries that rapidly deal lots of damage. Expired sentries now explode a wave of plasma instead of simply disappearing.

Path 2[]

LargerServiceAreaUpgradeIcon
Larger Service Area
COST: $250
UNLOCK: Requires Engineer Monkey

Description: Shoots further and deploys sentries in a much larger area.
Effect: Engineer gains +20 range, and sentries gain slightly more range.
DeconstructionUpgradeIcon
Deconstruction
COST: $350
UNLOCK: Requires Engineer Monkey

Description: Nail gun and Sentry shots do extra damage to MOAB class and Fortified Bloons.
Effect: Nailgun and newly deployed sentries deal +1 damage to MOAB-class and +1 damage to Fortified.
CleansingFoamUpgradeIcon
Cleansing Foam
COST: $800
UNLOCK: Requires Engineer Monkey

Description: Sprays foam that removes Camo and Regrow and pops Lead bloons.
Effect: Sprays foam anywhere on nearby bloon track. Bloons that hit the foam will permanently lose Camo and Regrow properties. Lead Bloons are neutralized and DDT Lead properties are removed.
OverclockUpgradeIcon
Overclock
COST: $13,500
UNLOCK: Requires Engineer Monkey

Description: Overclock Ability: Target another tower to supercharge its attack speed for a short time.
Effect: Ability temporarily increases attack speed of tower, range of a Monkey Village, or value of a Banana Farm. Ability duration depends on tier of the selected tower. Main attack gains more pierce.
UltraboostUpgradeIcon
Ultraboost
COST: $100,000
UNLOCK: Monkey Money1,500 (T5 Engineer Unlocks)

Description: Ultra-Overclocked Monkeys gain a small but permanent boost every time they are overclocked.
Effect: Ability now permanently applies a 5th of the bonus of Overclock onto the selected tower. Ability lasts twice as long on buffed towers. Increases the nail pierce even more.

Path 3[]

OversizeNailsUpgradeIcon
Oversize Nails
COST: $450
UNLOCK: Requires Engineer Monkey

Description: Massivization allows nails to pop 8 Bloons at once, including frozen. Also increases Foam and Sentry effectiveness.
Effect: Nailgun pierce increases from 3 to 8. Pierce of regular sentries increased from 2 to 3 and foam increased from 20 to 30.
PinUpgradeIcon
Pin
COST: $200
UNLOCK: Requires Engineer Monkey

Description: Pins Bloons in place for a short time when struck.
Effect: Nailgun nails pin any non-blimp bloon other than Leads and Ceramics. Can give Pin effect to all newly placed sentries as well.
DoubleGunUpgradeIcon
Double Gun
COST: $350
UNLOCK: Requires Engineer Monkey

Description: Two guns for twice the fun.
Effect: Double nailgun attack speed.
BloonTrapUpgradeIcon
Bloon Trap
COST: $3,600
UNLOCK: Requires Engineer Monkey

Description: Bloon trap captures Bloons until full. Tap to empty full trap for cash.
Effect: Produces a Bloon Trap that captures up to 500 RBE worth of non-blimp bloons, giving $1.5 per RBE for natural bloons and $0 per RBE for player sent bloons. Collecting the full trap earns $750 cash. Traps cannot produce faster with external speed buffs.
XXXLTrapUpgradeIcon
XXXL Trap
COST: $54,000
UNLOCK: Monkey Money1,500 (T5 Engineer Unlocks)

Description: Huge Bloon traps can trap some of the largest Bloons in them...
Effect: Produces a huge XXXL Bloon Trap that captures up to 10,000 RBE worth of almost any bloon including all non-BAD blimps, giving $0.75 per RBE for natural bloons and $0 per RBE for player sent. Collecting the full trap earns a bonus $7500 cash.

Strategy[]

Summary[]

Engineer Monkey mostly fulfills a supporting role in defense, though it has a reasonable early-game role too. At base, it is very similar to Ninja Monkey, having almost same stats and cost. It has a variety of supports, including the speed-boosting Overclock that can also boost Farm income, as well as Bloon Trap which can syphon natural bloons for money and can protect exits. Engineer also has some powerful damaging towers, including Sentry Expert's mid-game specialization and Sentry Champion plasma sentries for late-game damage.

Tips[]

  • Try to buy the sentries in advance before groups of bloons overwhelm.
  • Early-game Engineer as the primary defense can be quite expensive compared to other towers like Dart and Tack.
  • Engineer Monkey is highly recommended to only use in maps where the natural bloon lane is separated from the lane for enemy bloon sends (e.g. Bloontonium Mines, Docks), which means you can collect money from natural bloons with Bloon Trap upgrade without the disturbance of enemy send bloons. By choosing these types of maps, it can significantly boost your money income from Bloon Traps.
  • If you are using Engineer as early defence, make sure to place at least 2 Engineers with good upgrades such as 203 OR 302 and later sell them for 402 Sentry Expert just before Round 11.
  • Sentry Expert can serve as the Engineer's primary mid-game defense, which is helpful particularly in combination with Bomber Ace.
  • Since most Engineers lack camo detection without using Cleansing Foam to decamo the Camo Bloons, it is helpful to give them camo detection, particularly for Sentry Expert.
  • 520 Sentry Champion is a good and cost effective support against BADs. It is also decent at handling Fortified DDTs.
  • The 030 Cleansing Foam can reveal camo and remove lead properties from DDTs, making it a powerful combination with The Tack Zone.

Further Strategies[]

Monkey Mastery[]

Monkey Mastery is unlocked once all of its upgrades are unlocked. Monkey Mastery gives customization which is purchased using XP and Monkey Money. Has a total of 9 customizations available.

Item Type Description Cost Notes
Placeholder other
Gadget Copter
BTDB2-PlacementAnim-Icon
Placement Animation
Go Go Engineer! Monkey Money600
Tower XP75,000
TBA
Placeholder other
Eureka!
BTDB2-Emote-Icon
Emote
I've got it! Monkey Money160
Tower XP20,000
TBA
Placeholder other
Hard Hat
BTDB2-BloonDecal-Icon
Bloon Decal
Safety first! Monkey Money200
Tower XP30,000
Bloons wear Engineer's hard hat.
Placeholder other
Sparkling Trails
BTDB2-Trail-Icon
Trail Effect
They're meant to do that! Monkey Money450
Tower XP60,000
Sparks appear when attacking. Also affects sentries.
Placeholder other
Iron Monkey
BTDB2-Avatar-Icon
Avatar Icon
I am Iron Monkey Monkey Money300
Tower XP40,000
Messages translate to “I am fergus man, I’m a junior guy, is this good?” and “I’m not a bad guy, pls don’t sue” in Monklish.
Placeholder other
Repair Arm
BTDB2-IdleAnim-Icon
Idle Animation
Need a hand? Monkey Money450
Tower XP60,000
Robot arm appears out of hard hat and repairs nailgun.
000-EngineerMonkey
Named Engineer Monkeys
BTDB2-CustomNames-Icon
Custom Names
Name your Engineer Monkeys! Monkey Money300
Tower XP40,000
Default name is Scotty.
Placeholder other
Gadget Balloon
BTDB2-SellAnim-Icon
Sell Animation
Balloon, not bloon. Monkey Money240
Tower XP30,000
Flies off in a handheld hot air balloon.
Placeholder other
Open Sentries
BTDB2-WeaponSkin-Icon
Weapon Skin
Don't touch the wires. Monkey Money450
Tower XP60,000
Opens sentries up, exposing their wires.

Version History[]

Balance changes[]

The Engineer used to be moderately more popular than its Battles 1 counterpart due to stronger synergies with Overclock being available, as well as pure eco strats becoming more viable. Initially, it was used significantly due to being a near hardcounter to Bloon income strats thanks to Bloon Trap, then dropped off after Banana Farm’s prominence rose. It was believed that in a Farm meta, Engineer wouldn’t be viable due to it countering his strongest upgrade, and this caused Engineer to be used less and less. However, new discoveries and strats have shown that it actually works remarkably well alongside Farm due to drastically boosting its income, as well as XXXL trap and Overclock being great upgrades irrespective of the type of eco your opponent is using. While not having much diversity in its loadouts, the strategies it had were very strong. The most popular Engi loadouts included Darling-Engi-Farm and Dartling-Engi-Heli.

However, after eco changes making it much harder to get an early Bloon Trap and the recent nerfs making it unable to spawn quickly while allowing manual targeting simultaneously, Engineer fell out of the meta hard. Despite this, Engineer was hit with another major nerf in that it now only obtains money from natural bloons (albeit more money). Engineer is now considered to be one of the worst towers in the game.

For hero choice, it is often relegated to the strongest overall hero during that time, and not because they synergize with the Engineer directly. This is often Obyn as well as Ezili and Smudge cat Ezili.

Initial release (compared to BTD6 Version 28.0)
  • Change Bloon Traps now give exactly $700 when manually collected instead of a variable amount of cash.
  • NERF Bloon Traps cannot be autocollected
  • Change XXXL Traps now give exactly $7000 when manually collected instead of a variable amount of cash.
  • NERF XXXL Traps cannot be autocollected
  • BUFF Cleansing Foam has more pierce (10 → 15)
  • BUFF Cleansing Foam's foam is now locked on Close instead of randomly placed.
  • BUFF Cleansing Foam now strips lead property off DDTs.
  • Change Sentry Champion (formerly Sentry Paragon in BTD6) remains as "Sentry Champion"
1.0.6
  • BUFF 1xx Sentry Gun sentries reload time decreased (1s → 0.98s)
  • NERF xx5 XXXL Trap money given decreased ($7000 → $5000)
1.1.1
  • NERF xx4 Bloon Trap money given decreased ($700 → $500)
1.5.0
  • BUFF x3x Cleansing foam pierce increased (15 → 20)
  • BUFF xx1 buff to cleansing foam increased (+5 → +10)
1.6.1
  • NERF xx4 Bloon Trap and xx5 XXXL Trap can no longer be buffed by attack speed buffs such as overclock.
  • NERF x4x Overclock buff to banana farm reduced from x1.67 to x1.5
1.7.1
  • Change Bloon Trap without Larger Service Area now defaults to "Dynamic Targeting" instead of Manual Targeting
  • NERF xx4 Bloon Trap now requires Larger Service Area to utilize Manual Targeting.
  • Note: Ninja Kiwi stated "xx4 Bloon Trap: Manual targeting of the trap is now unlocked with the x1x Larger Service Area upgrade." but never mentioned some undocumented interactions related to Bloon Trap
1.7.2
  • NERF xx4 Bloon Trap Sent bloons are now worth $0 per RBE (formerly $1)
  • BUFF xx4 Bloon Trap Natural bloons are now worth $1.5 per RBE (formerly $1)
  • NERF xx5 XXL Trap Sent bloons are now worth $0 per RBE (formerly $0.5)
  • BUFF xx5 XXL Trap Natural bloons are now worth $0.75 per RBE (formerly $0.5)
1.8.0
  • BUFF 5xx Sentry Champion sentry attack rate decreased (0.06 → 0.05)
  • BUFF 5xx Sentry Champion sentry explosion pierce (40 → 100) and damage (100 -> 150) from selling increased
  • BUFF xx4 Bloon Trap cooldown decreased (12s → 9s) and respawn time decreased (2.8s -> 2.1s)
  • BUFF xx4 Bloon Trap cash per natural bloon RBE increased ($1.5 → $1.7)
  • BUFF xx5 XXL trap cooldown decreased (2s → 1.5s) and respawn time decreased (2s → 1.5s)
1.8.2
  • BUFF xx4 Bloon Trap Cash per natural bloon RBE increased ($1.7 → $2.4)
  • BUFF x5x Ultraboost price decreased ($120k → $100k)
1.9.0
  • BUFF 5xx Sentry Champion Sentry pierce increased (5 → 6)
  • Change xx4 Bloon trap will now always target the closest track spot unless changed with x14 targeting option.
1.10.0
  • NERF x5x Ultraboost max stacks reduced (10 → 5)
  • BUFF x5x Ultraboost each stack attack cooldown reduction changed from 4% to 8%
For such an expensive upgrade, it takes too long to get the full effect from this upgrade, and so we have doubled the effect from each buff in order to help with this.
~ Ninja Kiwi
2.0.0
  • NERF xx4 Bloon Trap cash per natural bloon RBE reduced ($2.4 → $2)
  • NERF 4xx Sentry Expert red sentry spiked ball pierce reduced (22 → 16)
  • BUFF 5xx Sentry Champion sentry attack cooldown reduced (0.05 → 0.044)
  • BUFF 5xx Sentry Champion sentry explosion damage from selling increased (150 → 200)
The bloon trap gave too much cash in comparison to other income sources so we are reducing it to be more in line with other towers. To compensate for this, we are buffing its late-game damage output to make it a stronger offensive tower.
~ Ninja Kiwi
2.0.4
  • BUFF Engineer Monkey base cost decreased ($450 → $400)
  • BUFF Double Gun cost decreased ($500 → $450)
  • BUFF Sentry Champion sentry attack cooldown decreased (0.044s → 0.035s)
We are making some small changes to try and make Engineer a more viable starting tower. Note that xx3 pierce is correctly 8 despite reports that it is not. Our previous buff to Sentry Champion was a step in the right direction but not quite significant enough, so here’s a bigger buff that should be more impactful.
~ Ninja Kiwi
3.1
  • BUFF Double Gun cost decreased ($450 → $350)
  • NERF Bloon Trap cost increased ($3500 → $3600)
    • Total cost remains unchanged
This upgrade is not efficient enough to be used as an alternative to Engineer's other options, so we are making a price cut to encourage its usage. Bloon Trap’s price has been increased so that the total cost for it remains unchanged, since it did not need a buff.
~ Ninja Kiwi
3.3
  • BUFF Sentry Gun cost decreased ($500 → $450)
  • BUFF Faster Engineering cost decreased ($400 → $350)
  • BUFF Pin cost decreased ($220 → $200)
  • NERF Sentry Champion cost increased ($2,500 → $2,800)
    • Total cost is increased by 200
  • NERF Bloon Trap max cash per trap decreased from $1000 → $750
  • BUFF Sentry Champion: Champion Sentries deal 200 → 260 damage when they explode
  • BUFF Sentry Champion: Champion Sentry attack rate 0.035 → 0.03
Engineer’s early game upgrades aren’t great, nor is 5xx. However, Engineer has some incredibly strong upgrades, being xx4 for a huge boost in cash and 4xx for easy mid-game defense. We have altered all of these upgrades, weakening its strong points while improving its weaker ones to compensate and balance it out.
~ Ninja Kiwi
4.0
  • BUFF Ultraboost: the temporary Overclock buff now lasts twice as long (30s → 60s on Tier 5 towers)
We're giving small boost to Ultraboost to help justify its incredibly high price tag
~ Ninja Kiwi
4.0.2
  • BUFF Overclock buff now applies to boosted tower's sub-towers too
This change makes sense for most child towers such as Etienne’s drones and Buccaneer’s planes, as without it they were unfairly unaffected by Overclock. This also offers a pretty decent buff to Engineer’s sentries, particularly 5xx, however we are keen to see how it goes since this isn’t a very strong upgrade at the moment.
~ Ninja Kiwi
4.1
  • BUFF Sentry Champion: sentry damage increased (2 → 3)
  • NERF 1+-x-x Engineer: attack rate buffs no longer increase sentry spawn rate
Recently, we altered Overclock so that buffing a parent tower will also buff all of its child towers (egsic sentries). Additionally, in this update we’re fixing a bug with this, meaning that newly spawned child towers will now correctly inherit the buff. With these changes, it makes Sentry Champion incredibly strong but only when buffed up a lot by the likes of Homeland Defense and Overclock. We have decided to change Engineer so that the spawn rate of its sentries can no longer be affected by attack rate buffs, but we have also greatly increased Sentry Champion’s regular damage so that it’s much stronger on its own now.
~ Ninja Kiwi
4.2
  • BUFF Sentry Gun: $450 → $400
  • BUFF Sprockets: $525 → $500
A couple of minor tweaks to help out Engineer’s early game defense.
~ Ninja Kiwi

Bug Fixes and General Changes[]

2.11
  • BUFF Fixed Engineer’s Open Sentries weapon skin not applying to Sentry Expert sentries.
2.2
  • BUFF Fixed Engineer Traps spawning over the empty lift shaft on Bloon Bot Factory.
  • Change Fixed Engineer’s sentries not spawning with the same targeting as the Engineer.
4.1
  • BUFF Fixed Overclock not affecting sub-towers spawned after the buff was applied.

Gallery[]

Official artwork[]

Videos[]

TBA

Trivia[]

  • For a long time after release, many players believed that double gun was bugged to have 5 pierce increase of 8. However, this might be a myth since in the 2.0.4 patch notes, Ninja Kiwi stated that such bug doesn’t exist. It’s possible that the bug was fixed before, but wasn’t documented.