Strategy:Alchemist (BTD6)

This article was last updated for: version 47.0

The Alchemist is a tower primarily used for support purposes. Its main draw are the buffs that the top path can provide that can significantly improve a player's defenses. Its income generation from bloons is decent in early-to-midgame rounds with Lead to Gold and Rubber to Gold. Middle path and the lower-tier upgrades offers supplementary damage.

Base

The base (0-0-0) Alchemist can be useful as a way to deal with early-game leads (rounds 28 and 30) as it is more reliable than other cheap options such as 0-0-0 Bomb Shooter. Its cost ($595 on Hard) is more than the Bomb Shooter, meaning it is less useful on game modes where cash is important (Half Cash, Impoppable and CHIMPS).

Upgrades

Tier 2 and below

• Perishing Potions does fairly high damage against Fortified MOAB-class for its cost, and for top path Alchemists its supports last longer.
• Faster Throwing is more efficient as a crosspath, and mainly for top path Alchemists to support towers faster.

Path 1

The top path Alchemist is incredibly versatile and can improve almost any strategy.

• 2-x-x Acidic Mixture Dip is useful for cheap lead popping power, bonus Ceramic damage, and MOAB-Class damage. It is one of the few lower-tier upgrades that is still useful late-game, as it is a cheap MIB skip for DDTs for towers like Bloon Exclusion Zone while boosting towers' damage to Super Ceramic Bloons and blimps.
• 3-x-x Berserker Brew is a nearly universal support and is useful in all stages of the game.
• 4-x-x Stronger Stimulant significantly improves Berserker Brew's buffs. Compared to 2 Berserker Brews, Stronger Stimulant shines when buffing expensive, fast-attacking, or low-pierce towers, but it falls behind otherwise due to having 1 less Acidic Mixture Dip.
• 5-x-x Permanent Brew is usually worse than simply having multiple Stronger Stimulants, as it is less cost-effective for most strategies. However, it still has strong use cases in CHIMPS, such as with Destroyers, Full Auto Rifles, or Druid of Wrath + Poplust spam.
• Perma-Brew can be moved around the map using a Support Chinook; this allows it to give permanent buffs to all towers. This is useful in Freeplay and Boss Bloon Events.
• The best crosspath depends on the situation: x-2-x Perishing Potions significantly improves the number of shots the potions can buff, and it is recommended when buffing fast-attacking towers like Sun Avatar. When buffing slow-attacking towers, such as Perma-Spike, use x-x-1 Faster Throwing, as x-x-1's faster buff potion reload outweighs x-2-x's increased duration when the number of shots x-x-1 can buff is not the limiting factor. x-x-2 Acid Pool is redundant.
• Do not use the top path Alchemist when fighting Lych, as Lych will remove the buff from towers and heal itself in the process.

Path 2

The middle path is more niche, but offer powerful damage under the right synergies.

• x-3-x Unstable Concoction is powerful against blimp-heavy rounds like 94, 96, and 98, where the explosions deal extreme damage. However, it can create dangerous Super Ceramic rushes.
• x-4-x Transforming Tonic is a powerful tower for its cost, shining in both mid-game and late-game. However, its reliance on its ability limits its usability for Black Borders in CHIMPS, as getting the timing right for certain rounds can be RNG-dependent.
• x-5-x Total Transformation is expensive. Nonetheless, it is exceptional in specific strategies with Shinobis or Druids of Wrath (the latter being buffed with Poplusts). Total Transformation also pairs well with Plasma Monkey Fan Club, as the two abilities can be combined for 100% uptime.
• For all three upgrades above, x-x-1 Faster Throwing and 1-x-x Larger Potions are roughly on-par for crosspathing purposes, The former provides stronger single-target damage, but the latter provides far superior grouped popping power.

Path 3

The third and fourth upgrades of bottom path make income from bloons. The fifth upgrade loses income in exchange for removing strong targets weaker than a BAD.

• x-x-3 Lead to Gold is useful for money generation against Dreadbloon, which has custom rounds that greatly increase the abundance of Leads. It otherwise sees niche use for money generation on lead-heavy rounds such as Rounds 37 and 38.
• x-x-4 Rubber to Gold is useful as a cheap money maker, as its effects stack with Monkey Town and other buffs. On blimps, it works best with towers that one-shot them, most notably XXXL Trap and Pirate Lord.
• x-x-5 Bloon Master Alchemist (BMA) can be deadly with proper support, but it falls off past Round 100 due to its inability to hit BADs. The BMA also suffers from the same issues as Benjamin's bloon trojan; it severely affects income as its shrink potion does not give any cash.