Round 63 (BTD6)

"If you have played Bloons TD5 you'll remember what round 63 was like. If you are new to this game, let's just say: many tightly packed Ceramic Bloons."

- BTD6 Pre-Round Comment for Round 63

Round 63 is a round in Bloons TD 6. The round consists of groups of Lead Bloons, followed by three distinct waves of super-dense Ceramic Bloons. It remains fairly similar to its BTD5 counterpart, but it has some key differences. In fact, the distinction in BTD6 is the almost fully clumped waves of Ceramics per wave.

Description
There will be a constant wave of Leads followed by each wave of super dense Ceramic Bloons. The first wave of 40 Ceramics will spawn in after ~3.9 seconds from when the round starts. The second wave of 40 Ceramics will spawn in after ~16 seconds from when the first wave appears. The third and final wave is very slightly stronger, with a wave of 42 Ceramics, and will spawn in after ~16 seconds from when the second wave appears.

Summary
Round 63 is one of the most difficult mid-game rounds in the whole of BTD6 due to how densely packed the Ceramic waves are at such an early stage of the game, making this round quite difficult to pass through on many CHIMPS games. Usually, the Ceramics are the most problematic part of the round, but the Leads are equally as dangerous too, making it harder for sharp-based towers to destroy the Ceramics. Due to the density of the Ceramics, and especially of their children, high-pierce towers are recommended. Towers that slow down the Ceramic clumps, such as Ice Monkeys, are also helpful. The best combination of counters to this round are generally those that hybridize high pierce and stalling, such as Icicles, but very high pierce towers such as properly timed Blade Maelstrom abilities work too.

The best low-cost countermeasures against Round 63 is a combination of high pierce and reliable slowdown. The use of slowdowns help reduce the speed of the rushed bloons, adding time for the defense to handle the bloons, while high-pierce towers destroy the extremely dense groups of Ceramics and the bloons underneath. Many of these countermeasures often involve abilities. Try making use of the selected hero in the game to assist with beating this round. Charging abilities before the round starts is very helpful, as the first wave of dense Ceramics come in quite quickly, and most activated abilities in this game have initial cooldowns.

Round 63 is a very popular round in custom challenges, including several Advanced Challenges, which often involves a solution involving a set of strong towers, usually with Glue and/or Ice.

Tips

 * The best single counter to Round 63 is an Icicles. 2-0-4 Icicles helps beat the Leads while also being able to apply Permafrost effects to the clumps of Ceramics, slowing the Ceramics down immensely. 0-2-4 Icicles on the other hand helps apply large damage to the clumps of Ceramics while also freezing them in place.
 * If on a low budget, adding a low-level Ice Monkey is a good option for countering Round 63, even with a 0-0-0 Ice Monkey. This helps slow progress of the bloons so that the defenses will get less overwhelmed. 1-0-0 Ice Monkey applies Permafrost that can be used to slow down Ceramics even further. 0-1-2 Ice Monkey near-permanently stalls down the Ceramics in place and cracks them into much weaker groups of bloons given enough time. The Ice Monkeys also will ignore the Leads, allowing other towers to pick them off as well.
 * If given a good curve to maximize its coverage, a 410 Ice Monkey can not only stall the hyperdense Ceramics but also make them take more damage, thus allowing the player's other towers to destroy them faster.
 * A 2-0-4 Recursive Cluster, on Strong or First, can help defeat Round 63 by beating the big Ceramic groups with it's big cluster. You can combine it with a 3xx or 4xx Alchemist for more popping power, and you don't need Striker Jones or a MIB because the Frag Bombs 28.0 buff allows xx3 bomb and above to have Normal type.
 * When it comes to use of heroes, there are certain heroes that naturally excel on beating this round. Hero abilities can be used to help beat this round, including both of Gwendolin's abilities, Etienne's UCAV, Quincy's Storm of Arrows, Captain Churchill's Armor Piercing Shells, and Obyn Greenfoot's Wall of Trees.
 * Monkey Sub strategies can use Sub Commander to combat 63, due to it greatly increasing pierce and damage.
 * Blade Maelstrom possesses a very high amount of pierce, and it is one of the best cheap options for countering Round 63 in the presence of lead-popping sources. Time its ability properly to deal with each wave. Its cooldown is quite fast for an activated ability, so it can have enough uptime to deal with the first and last waves. In fact, two Blade Maelstroms are sufficient for countering the Ceramics reliably.
 * Due to the round's 75 Lead Bloons, a single Lead to Gold alchemist will easily make a small profit on this round. If the alchemist catches all 75 Leads, they will generate a total of $3750.
 * Similarly, Round 63's groups of Ceramics are effective for Rubber to Gold to gain a considerably high profit. If it can hit all 122 Ceramics with the Gold effect, a maximum of $4280 can be profited this round (adds a +$0.4 per pop on this round, which allows each pop to gain $0.6 per pop instead of $0.2 per pop).
 * A crosspathed Elite Sniper coupled with a Stronger Stimulant can easily solo Round 63 in entirety, as the Bouncing Bullets will shred through the Leads and Ceramic waves easily.
 * A Spectre or Apache Dartship can single handedly defeat this round. However, both of them are expensive.
 * Although expensive, a 4-2-0 Bloon Impact can be used to both counter the Leads, stun large waves of Ceramics, and deal big damage to the densely clumped Ceramics, provided there is adequate cleanup against the weaker bloons. It has a decent 50 pierce and reasonable attack speed. Set on Strong for the best results.