
Acid Spray
Sprays high-pressure acid across a target area. Enemy units who step across the contaminated terrain take damage per second and have their armor reduced.
Abilities, roles and builds with an explanation for every purchase.

HERO GAME PLANI accelerate my economy and use my item advantage before the enemies catch up in strength.
Synthesizing extra resources from each and every kill, Alchemist has no trouble gathering the tools needed to destroy his foes. Ambushing enemies with corrosive acid and a host of unstable chemicals, he battles to ensure his greedy escapades can remain uninterrupted.
My recommendation is a starting point. We choose another position together with the team and for its needs.
I need protected farm, my item window and damage on important targets.
Levels, lane control and joining the team at the right moment matter.
This is an editorial starting plan based on hero mechanics. It is not presented as a match I have already tested or a popularity ranking.
Here is my initial plan: I do my role's job first, then choose the items the team needs. I adapt the order and expensive purchases to the opponent.

Help maintain close contact and pass through groups of units.

Speeds up farming and pressures nearby enemies with constant damage; an expensive investment that needs time to pay off.

Changes the entry angle and lets me reach a target quickly. Damage taken can prevent its use.

Provides a window for my actions against eligible magical damage and disables. I check effects that pierce the protection.

Gives the team armor and attack speed, helping it apply physical pressure to heroes and objectives.

I do not assign one ‘correct’ minute to every purchase. I look at my gold, the next fight and the problem: am I missing mana, target access, control or protection? If an expensive slot will arrive too late, I get a useful answer earlier.
Original Valve icons and descriptions. Cooldowns and mana are shown by level from the data snapshot; talents and upgrades can change the values.

Sprays high-pressure acid across a target area. Enemy units who step across the contaminated terrain take damage per second and have their armor reduced.

The hero begins shaking a vial of unstable chemicals that can be thrown at an enemy hero. On impact, the vial explodes, stunning and damaging all enemies in the blast radius.
Alchemist brews up an unstable concoction that he can throw at an enemy hero, to stun and deal damage in an area around the explosion. The longer the concoction brews, the more damage it deals and the longer the stun. Alchemist is faster while charging the concoction. After 5 seconds, the brew reaches its maximum damage and stun time. However, after 5.5 seconds, the concoction will explode on Alchemist himself if not thrown.

The hero enhances his weapons and abilities with acid that reduces his victims’ movement speed and base damage. This effect stacks.
Alchemist coats his weapons and empowers his spells with an acid that applies a stacking slow and base attack damage reduction to enemies hit. Attacks apply 2 stacks. Unstable Concoction applies 1 stack per second of brew time.

A special chemical mixture enrages the hero, reducing his base attack time and increasing his movement speed and health regeneration.
Alchemist causes his Ogre to enter a chemically induced rage, reducing base attack cooldown and increasing movement speed and health regeneration. DISPEL TYPE: Basic Dispel
These abilities are not necessarily available at the same time. I check the condition beside the name: innate ability, another form or an Aghanim purchase.

Throws a potion at an ally, applying a basic dispel, increasing health regeneration and granting attack and movement speed.
Alchemist throws a potion at an ally, applying a basic dispel and giving them attack speed, movement speed and HP regen. DISPEL TYPE: Basic Dispel

Generates extra gold from enemies and runes. Bonus gold from unit kills has two parts: a base bonus and an increasing bonus for each unit killed within 40 sec. of the previous one.
Alchemist synthesizes additional gold from his enemies and bounty runes. With each kill, Alchemist earns base bonus gold and extra bonus gold. If Alchemist kills another unit which yields gold within the next 40 seconds, an additional instance of Extra Bonus Gold is added to the total. Additionally, causes bounty runes to yield more gold.
The hero can melt an Aghanim's Scepter to give an ally all its upgrades, while gaining +15 attack damage and +3 to the base and maximum gold from Greevil's Greed. The bonuses gained from melting multiple scepters stack.
These are fields from the official source. The hero's final values in the client account for attributes and other active mechanics.
Items, slang and real episodes help connect abilities with what happens in a match.