Strategy:Impoppable (BTD6)

This article was last updated for: version 46.3

Impoppable has 100 rounds, significantly more than Hard Standard. This leads to Super Ceramics on Rounds 81+ and exceedingly difficult rounds such as 95 and 98 appearing in standard gameplay, making the late-game far more difficult. In addition, all towers are ~11.1% more expensive than in Hard Standard. Therefore, farming greatly assists in beating Impoppable by allowing high-cost, high-power setups that coast through the late-game to be afforded. The Round 6 start and 1 life greatly increase the early game's difficulty, thus requiring a proper early-game strategy as well.

For purposes of clarity, the following definitions will be made for this article:

Early-game = Rounds 6-40
Mid-game = Rounds 41-80
Late-game = Rounds 81-100

General tips

Preparation

• It is recommended that significant amounts of Monkey Knowledge upgrades have been acquired before going into Impoppable. Important ones include Pre-game Prep, Bonus Monkey!, More Cash, Military Conscription, and Veteran Monkey Training. Each one of them greatly reduce Impoppable's difficulty.
• It is recommended to beat Hard Standard on a good amount of maps before touching Impoppable. That game mode grants large amounts of Player XP for Monkey Knowledge points, is relatively simple to complete, and opens part of the pathway to Impoppable on these maps.
• Practice farming while doing these games, as farming becomes important in Impoppable. Attempt to perform slight farming while having a robust defense during the practice.

The most challenging rounds in Impoppable

Round #	Bloons spawned	Reasoning
40	MOAB ×1	The MOAB is the final challenge of the early-game, and the player can easily succumb to over-greeding on this round. Without a proper setup to deal good single-target damage and clean up the tight, high-RBE ceramics, this round could pose severe challenges.
63	Lead ×75 Ceramic ×122	This infamous round has 3 tight Ceramic waves with 40, 40, and 42 Ceramics respectively. One ability cannot handle all 3 waves, so if using abilities, 3 ability towers or selling and rebuying is needed. Towers that excel in grouped damage are required to beat this round.
75	Lead ×14 Fortified Lead ×14 Fortified MOAB ×3 BFB ×6	The 6 BFBs in 3 separate packs, especially the last dense pack of 3 BFBs, the fortified MOABs, and the Leads blocking many projectiles can stumble many strategies that cannot deal both strong single-target damage and solid grouped popping power.
78	Rainbow ×150 Ceramic ×75 BFB ×1 Purple ×80 Camo Ceramic ×72	Without a solid Camo popping power or reliable decamo, the densely packed Camo Ceramics will easily cause a sudden loss.
90	Fortified Camo Regrow Lead ×500 DDT ×3	The 3 DDTs can easily catch new players off-guard, due to them being fast-moving blimps as opposed to slow-moving ones with Super Ceramics as the main threat. Not noticing them while without towers that can pop Camo, Black, and Lead will cause a sudden loss.
95	Fortified Camo Regrow Lead ×500 Camo Regrow Purple ×250 Fortified MOAB ×50 DDT ×30	The extreme amount of DDTs presents a massive challenge to many strategies. The Fortified MOABs and their Super Ceramic insides consume the pierce of projectiles that would have damaged the DDTs, posing further challenges.
98	Fortified BFB ×30 ZOMG ×8	This round has the highest RBE out of any round in pre-Freeplay Impoppable. The high health of the fortified BFBs and ZOMGs, but especially the absurd amount of Super Ceramics (including Fortified) that they contain, make this round exceedingly difficult.
99	MOAB ×60 Fortified DDT ×9	Many strategies that beat 95 fail due to having grouped DDT damagers that fail as DDTs gain 2x health on this round. MOABs and their insides continue to consume pierce. Unlike 95, ability cooldowns can be fatal, with DDTs spawning right after the notorious Round 98.
100	BAD ×1	Many strategies that revolve around stalling and/or grouped popping powers completely fail to Round 100 due to the BAD being immune to all slowdowns from towers and requiring single-target damage options to be dealt with.

Gameplay

• Farming is key in Impoppable, as the higher prices and difficult 90s rounds often necessitate strong and costly defenses that are not affordable without farming.
• Do not over-farm either, as over-greeding can lead to a loss. Round 40 is the round that most often spells trouble for setups with too much farming. Have a robust defense while doing light to moderate farming.
• Supporting towers shine, especially in the 90s. Jungle Drums, Berserker Brew, and Stronger Stimulant are useful even in the mid-game, while Giant Condor, MOAB Glue, Relentless Glue, Bloon Sabotage, MOAB Press, and Symphonic Resonance aid greatly if no high-cost late-game carry towers can be afforded.
• Do not be afraid to sell towers when needed. Situations that necessitate selling includes affording the Hero early and affording the expensive late-game carry.

Towers & heroes suited for most maps

Name	Portrait	Reasoning & how to use
Monkeyopolis		Usually obtained in the 40s or 50s, Monkeyopolis's Monkey Commerce discounts, Monkey Town granting more cash per Bloon pop, Monkey City buffs to surrounding money-makers, and production of $1200 per round when absorbing one 0-0-0 Banana Farm make it the most efficient money-maker and allows for a trivial late-game. Once Monkeyopolis is obtained, attempt to place all damaging towers and farms in its range, and the 2-0-5 crosspath is optimal to increase its range and grant Jungle Drums. The best way to obtain it is to first buy 3 0-0-2 Monkey Commerces close together, buy a Monkey City discounted by all 3, sell one Monkey Commerce, get a 0-0-0 Banana Farm discounted all 3 villages left, sell the other two Monkey Commerces, and finally upgrade the Monkey City into Monkeyopolis.
Benjamin		Ben's money generation creates a snowball effect, allowing vastly increased farming speed in addition to more defense being able to be afforded. With Monkey Education, Self Taught Heroes, and Monkeys Together Strong, he can be used as the only farming tower on the screen, as he reaches Level 17 fast enough for the 90s. Otherwise, it is recommended to take advantage of his early money-making to get a Monkeyopolis in the 40s-50s. Biohack is useful in the early-game, but must be used carefully. If placed without line-of-sight blockers, Trojan is very helpful against Round 40, but loses some money later on. Attempt to afford Ben as quickly as possible by getting the bare minimum defense for the first few rounds, and sell one tower for Ben if doing so affords him.
Geraldo		When placing Geraldo between Rounds 6-10 (with later placements recommended for harder maps), Rare Quincy Action Figure generates very large amounts of money. There are two ways to take advantage of it: one is to sell it in the 30s for Monkey Bank, which would be sold in the 40s after it becomes full for Monkeyopolis to smooth-sail the rest of the game, while the other is to sell it on Round 81 for a very expensive tower that solos the game, such as Flying Fortress. In addition, See Invisibility Potion makes Camos much easier to deal with in the early-game, Gerry's Fire adds solid extra damage throughout the game, Genie Bottle simplify difficult late-game rounds, and Jar of Pickles helps low-damage towers greatly. All of these grant Geraldo versatility in Impoppable and make him a great choice on all maps.
Airburst Darts		2-0-2 Airburst Darts is an excellent early-game tower that also takes care of Camos when using 0-0-2 Dart Monkeys as Camo Intel. Berserker Brew greatly amplifies its power and gives it lead-popping power via Acidic Mixture Dip, and it can be upgraded into Triple Guns and then Armor Piercing Darts for further increased power into the mid-game.
Bloonjitsu		Bloonjitsu, when given Berserker Brew, can also cover all Bloon types and does good overall damage in the early-game and mid-game. Double Shot is a decent stepping stone that transitions relatively well with Bloonjitsu, and it is recommended to purchase Berserker Brew after Double Shot and before Bloonjitsu. While Bloonjitsu plows through the 40s, some farming can be done to save up for Monkeyopolis.
Neva-Miss Targeting, Spectre, Flying Fortress		2-0-3 Neva-Miss + Camo support + Berserker Brew easily defeats the early part of the mid-game, transitioning very well into Spectre. The 2-0-4 Spectre with a 2-2-0 Monkey Village solos through Round 80 on most maps, and can go further into the 80s on easier maps. With some farming using Monkeyopolis and farms surrounding it while Spectre plows through the 60s and 70s, by Round 81, $100,000 can be saved up for a very expensive tower that guarantees victory. 2-0-5 Flying Fortress + 2-2-0 Village fills this role perfectly, sweeping the late-game with absolute ease on nearly all maps and effectively guaranteeing victory. On the most difficult maps, use Bloon Sabotage or Overclock for Rounds 95/99, Carrier Flagship, or Permanent Brew with Fortress to guarantee the win.
Spiked Mines		Spiked Mines tanks large amounts of Bloons and blimps in the mid-game with Berserker Brew, preventing any sudden loss. It remains very useful against late-game Super Ceramics thanks to its bonus Ceramic damage. It is useful even on multi-lane maps when 2 of it is bought, and the 4-2-0 crosspath allows it to tank more Bloons, while the 4-0-2 crosspath is better on maps where targeting matters (such as Dark Dungeons).
Perma-Spike		Perma-Spike fully guarantees victory when paired with a very powerful damage tower, and is versatile thanks to being useful on nearly all maps. It can tank tremendous amounts of Bloons and blimps. Use the 1-0-5 crosspath, and give it a Jungle Drums village and 3-0-1 Berserker Brew (which in combination give it over 40% more tanking power).

Early game (rounds 6-40)

• The first few rounds generally follow the same strategy as in CHIMPS, but become much easier with the Monkey Knowledge upgrades of Pre-game Prep, Bonus Monkey!, and More Cash.
  • Dart + Boomerang is the best start without Monkey Knowledge on maps without good water placements.
  • With good water placements, Dart (on Strong for Greens) + Sub also excels without Monkey Knowledge. The following starting combinations require either Bonus Monkey! or More Cash.
  • Three 0-0-0 Darts work on nearly all maps.
  • Dart + Sniper (on Strong for Greens) is optimal on maps with range problems, such as Bloonarius Prime.
  • Dart + Engineer is similar to three 0-0-0 darts, with the Engineer being upgradeable to the very useful Sentry Gun.
  • Some maps feature unique starts. For example, Spillway's middle barrel makes a Ninja Monkey into 1-0-0 and then 1-0-1 ( does not require Bonus Monkey! or More Cash) the optimal start.
  • Once a robust starting set-up has been required, attempt to get the hero as early as possible, especially if Benjamin is used. When close to affording the hero, selling one tower to afford them is recommended. However, with Geraldo, it is best to hold off on purchasing him if selling is required to afford him so that Rare Quincy Action Figure can be bought.
• By Round 15, unless using Captain Churchill, the hero should have been acquired. Start building a solid set-up for the early-game during these rounds.
  • Airburst Darts performs exceptionally well on nearly all maps with water.
  • Wall of Fire easily takes care of Bloons that enter its fire. 1-2-0 is more reliable, but 0-2-2 is preferred if it is to be upgraded to Dragon's Breath.
  • One 0-0-0 into 1-0-0 Spike Factory reliably tanks leaking Bloons, including the Round 24 Camo.
  • 1-3-0 Druid of the Jungle is arguably the best choice on maps with 1 lane active per round.
  • Round 24's Camo can be tanked with enough Pre-game Prep spikes, but watch out for them if these spikes are not present. Watch out for Round 28's Leads as well.
  • On easier maps or with near-full Monkey Knowledge, it is possible to get a slight head-start into farming here. One 2-0-0 Banana Farm by Round 30 is a good starting point.
• For the latter part of the early game, Rounds 31-40, a start to farming is optimal. The defense should have both solid single-target and grouped popping power by the MOAB's appearance.
  • Attempt to get at least a 2-0-0 farm by Round 40. If on an easier map or with near-full Monkey Knowledge, purchasing a Monkey Bank in the 30s can work and sets the stage for an early Monkeyopolis and easier mid-game and late-game.
  • Destroyer does both solid MOAB damage and solid Bloon damage with the 3-1+-0 crosspath. Berserker Brew amplifies its power even further.
  • Upgrading Airburst Darts to Triple Guns grants it further increased power to deal with the MOAB and the early mid-game.
  • Dragon's Breath reliably pops all non-MOABs that it passes through its wall of fire, excluding Purples. It remains powerful through the mid-game.
  • Do not farm too hard in the rounds immediately prior to the MOAB's appearance.
  • Save the Hero's ability/inventory for the MOAB, by far the hardest challenge of the early-game. Also, purchase a robust defense with solid single-target and grouped popping power.

Mid-game (rounds 41-80)

• The hero steadily gains importance throughout the mid-game. Utilize their abilities/inventory when needed, and use towers that work well with them, such as Triple Darts for Geraldo (whose Sharpening Stone and Jar of Pickles both aid greatly).
• Berserker Brew/Stronger Stimulant should be purchased for the strongest mid-game tower(s). The damage, attack speed, and pierce buffs multiply the power of nearly all mid-game towers.
• Rounds 41-60 generally feature continued farming and getting a tower that carries the tower through the mid-game.
  • If a Monkey Bank has not been obtained, get it in the early 40s.
  • When the Monkey Bank fills up in the 40s to 50s, sell it and follow the procedure listed in the Towers suited for most maps section to obtain a Monkeyopolis.
  • Neva-Miss Targeting + Berserker Brew + Camo support can be obtained in the 40s. It easily defeats the early mid-game on nearly all maps and transitions well into Spectre.
  • Bloon Area Denial System is solid on most maps, and allows plenty of farming while it powers through the mid-game.
  • Artillery Battery easily cleans up Bloons, with its Bombardment ability being able to take down blimps and hyper-dense rounds. It works especially on maps with loops such as Dark Path and Moon Landing and with some micromanagement.
  • Aircraft Carrier performs strongly against both blimps and Bloons.
  • Spiked Balls and Spiked Mines prevent random leaks, which occur especially easily on short maps. Both carry power into the late-game, unlike most other towers listed here.
  • Plasma Accelerator deals solid MOAB-class damage and cleans up non-Super Ceramic Bloons fairly well. Place it so that it has a long-straight line to shoot down on, and focus its high-damage point at the end of the beam on the most dangerous clump of Bloons/blimps.
  • With good farming, Spectre can be obtained in the 50s. It carries through the whole mid-game with a 2-2-0 Monkey Village, and farming while it plows through the mid-game allows the on-time affording of virtually any late-game tower.
• During Rounds 61-80, if the mid-game defense has not been solidified, continue doing so in the 60s. One cheap late-game tower can be obtained, and if an expensive one is desired, attempt to farm well here to be able to obtain it before Super Ceramics pose too large of a challenge.
  • Spectre can be obtained in the early 60s if still desired.
  • To farm, build 2-0-3 Marketplaces around the Monkeyopolis, as they make good income for their cost and can be sold for higher returns thanks to Banana Salvage if needed.
  • Carrier Flagship solos the mid-game with relative ease on most maps and remains strong in the late-game.
  • Glaive Lord is a very solid win condition that remains extremely powerful in the late-game.
  • Perma-Spike tanks very large amounts of Bloons and blimps and guarantees victory when combined later on with a powerful tower. Pair it with Berserker Brew.

Late game (rounds 81+)

• Super Ceramics start appearing on Round 81, posing trouble for many mid-game focused defenses that struggle against them. Towers that struggle against Super Ceramics include Recursive Cluster, Ring of Fire, and Crossbow Master, and it is recommended to sell them on Round 81 for better late-game options.
• In the 80s, attempt to get a 2nd late-game tower (listed at the end of the section above) or obtain the expensive late-game carry if it is desired. These late-game carry towers are listed here.
  • Flying Fortress + 2-2-0 Village fully guarantees victory on most maps. On True Expert maps such as Quad and Ouch, giving it some support will suffice. Recommended support towers are listed in the main bullet point below and Gameplay section above.
  • Ray of Doom works well on all maps where its ray can get a straight line down all paths.
  • Bloon Exclusion Zone is somewhat weaker than Fortress and Ray of Doom, but is more affordable and still guarantees victory with only some support on the majority of maps.
  • Pouākai likewise effectively guarantees victory on most maps, especially when merged with extra Golden Eagles for Max (132) Beast power. On harder maps, use Perma-Spike to guarantee victory by tanking its sporadic leaks and add extra defense for the BAD.
  • With an expensive late-game carry, Overclock is strongly recommended (except for Pouākai, which Overclock does not work on). Get two Overclocks if full uptime and reliability are desired.
• The 90s feature the most difficult rounds, and it is advised to purchase supporting towers here. Other late-game damage towers can also be dropped if extra cash is present.
  • Giant Condor can turn multi-lane maps into effectively single-lane maps and grants good utility by grabbing Bloons back near the start of the track.
  • Relentless Glue contains both the solid slow from MOAB Glue and solid stunning capabilities with its splats.
  • Bloon Sabotage is especially useful against DDT rounds such as 95 and 99, with the ability slowing them down by half. Note that it does not slow the insides that blimps pop into while the ability is active.
  • Symphonic Resonance can trance blimps into a ring that more towers reach and buys more time for their destruction.
  • MOAB Press does large amounts of knockback against blimps, being especially useful for dense rounds such as 98.
  • Permanent Brew, Call to Arms, and Homeland Defense can be bought if many damage towers are present and large amounts of spare cash is left. They further boost the damage towers' power, while speeding up the late-game rounds.
• If using many ability-reliant towers, be careful about their timings in the 90s. Attempt to leave at least 1 ability active at the start of every round, and if not, sell-and-rebuys may need to be performed. If the hard part of the round comes in quickly, as in Round 99, even selling-and-rebuying might not be enough. However, Geraldo's Rejuv Potion is useful for this scenario if he is used.
• For Round 100, if expensive and ultra-high damage towers such as Fortress are present, the round is usually trivial. If no BAD-damaging tower is present, selling-and-rebuying is needed to afford BAD-damaging towers, such as First Strike Capability (which one-shots the BAD when used slightly after the last damage phase), Spike Storm, or MOAB Eliminator.