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Construction and Refinery Guide - IdleOn

April 16, 2026

One of the first skills you learn in World 3 of IdleOn is the Construction skill that allows you to use salts from the Refinery to build towers. This guide will outline all the different Construction Towers you can build and the materials you need to produce salts.

As soon as you access World 3 Frostbite Tundra, you can unlock the Refinery and start producing salts. The Refinery will produce salts over time and you can then use these to build towers at the Construction table.

Refinery

Refinery

The Refinery will automatically take materials from your Storage and use them to produce Salts. A Combustion cycle happens every 15 minutes, but this can be decreased with various boosts within IdleOn.

You can unlock various other salts in the Refinery. Salts are required for Construction Towers and also crafting equipment, upgrading stamps, Alchemy and a host of other areas in IdleOn.

Refinery UI

You'll find at the beginning you often run out of Fuel Components needed to make Salts, so it's ideal to start using the 3D Printer to produce the items you need automatically.

When you click the Refine button, the salts will be deposited into your Output inventory. You can also move them to your Storage for crafting or upgrading.

When a Salt's power reaches 100%, you can upgrade it. This will then allow you to produce more salts, but it will also consume more materials.

You can also set your Salt to Auto-Refine at a certain % to help keep a healthy supply of Salts automatically being produced.

Salt Fuel Components Unlock Cost
  Default
    40 x Redox Salts
 

Fly

 
150 x Explosive Salt
    300 x Spontaneity Salts
      500 x Dioxide Synthesis
        750 x Purple Salt
   

Construction

Construction Table

The Construction Table is where you can build towers that offer various new mechanics to IdleOn.

There are three types of towers you can build:

  • World 3 Towers - These towers offer new features to World 3
  • Tower Defense - These towers are used in the Tower Defense mini-game/skill
  • Shrines - These shrines offer boosts whilst you fight mobs on maps

You can build up to 2 Towers at once by default, but you can unlock more tower building slots by purchasing the Tower Building Slots from the Gem Shop.

Each Tower has it's own maximum level; once you've build it once, you can then build it again to increase it's level. Each tower requires various components to be upgraded.

The rate at which a Tower is built is based on your Construction Build Rate.

Cogs

Cogs Tab

The Cogs tab at the Construction Table allows you to level up your Construction Skill passively. Cogs can give increase build rate, construction exp and Flaggy Rate.

When you open the Cogs Tab, you'll see a grid where you can place your Cogs. Cog grid slots can be unlocked by placing Flags on them. Once a Cog Slot reaches 100%, you can then place a Cog there. The aim is to unlock the entire grid so you can add more cogs and thus increase your building rate.

Cog Shelf

You can generate cogs by placing IdleOn characters on the Cog Shelf. You'll generate cogs over time and clicking the Collect button will add the Cog to your Cog Inventory (where it can then be placed on the grid).

You can also trash cogs you don't want to use.

Cogs can have the following stats:

  • Build Rate
  • Bonus Construction EXP
  • Flaggy Rate

Build rate increases your Tower Construction, Bonus Construction EXP increases your Construction Skill level (which in turn increases build rate) and Flaggy Rate increases how fast Flags unlock new Cog Slots on the grid.

You can unlock more powerful Cogs by increasing your Construction Level:

  • Nooby Cogs - Level 1
  • Decent Cogs - Level 15
  • Superb Cogs - Level 40
  • Ultimate Cogs - Level 70
  • Jewel Cogs - Level 70 (Must have Gaming Duperbits unlocked: Jewel Cogs)

Zen Cogs Zen Cogs Zen Cogs

You can also buy special Zen Cogs from the Gem Shop that have the best rates.

You can also place IdleOn Characters on the Cog Grid; it is best to place your Squire Class as they have the best Construction Rates available.

The best cogs to use are Bonus Construction EXP cogs as these will increase your Character's Construction Level, which will then boost your Build Rate much faster than any cog can perform.

Construction Towers

The max level of Towers can be increased by obtaining Construction Mastery at The Rift.

Tower Description Materials Max Level
3D Printer
3D Printer
Using the new Star Talent (on the 2nd tab of Star Talents), you can collect samples to start printing resources! 10
Talent Book
Talent Book Library
Relive your youth by checking out books, and further relive your youth by never returning them! Instead, use them to boost your talent max levels.   101
Death Note
Death Note
Defeat TONS of monsters to boost your Multikill Rate for each world. Upgrading this tower also boosts your base Multikill Bonus in all worlds. 51
Salt Lick
Salt Lick
Spend Refinery Salts and other World 3 Resources in return for bonuses from the hungry blobulytes! 10
Chest Space
Chest Space
Just gives more Storage Chest slots, straight up. I gotchu dawg, yeh. 25
Cost Cruncher
Cost Cruncher
Reduces the resource costs of upgrading buildings. Doesn't affect 'building' phase cost. 60
Trapper Drone
Trapper Drone
Remotely deploy AND collect traps to and from any discovered critter location! Collect-all is based on Hunter's Eagle Eye Talent. 15
Automation Arm
Automation Arm
Automate some of the more tedious actions with the flip of a switch! Let the robots do the dirty work! 5
Atom Collider
Atom Collider
Accelerate enough material to high speeds, and you can create the first physical atoms in this pixellated world! 200

Tower Defense

Tower Defense is a mini-game you can play using your Worship skill. You can build and upgrade the following towers to make the game more easier.

Tower Description Materials Max Level
Pulse Mage
Pulse Mage
Zaps a single nearby monster. Has fast speed, and low damage. 52
Fireball Tower
Fireball Lobber
Lobs exploding fireballs. Has medium speed, and medium damage. 52
Boulder Roller
Boulder Roller
Rolls a boulder forward. Has slow speed, and medium damage, but reliably hits multiple enemies. 52
Frozen Malone
Frozen Malone
Casts a wave of freezing snow. Has slow speed, but can stack it's effect with other Freeze Towers. 52
Stormcaller
Stormcaller
Smites enemies with lightning. Has super slow speed, but high damage. 52
Party Tower
Party Starter
Has no function other than its Trait Boosts. 52
Kraken Tower
Kraken Cosplayer
Summons eyeball defenders. Has slow speed, and just keeps monsters away. 52
Poison Tower
Poisonic Elder
Poisons enemies. Has slow speed but great AoE for hitting large crowds of mobs. 52
Voidinator
Voidinator
Casts a wave of null and void, removing enemy colors. 52

Shrines

Shrines

Shrines can be placed on any map using the Shrine Architect talent in Special Star Talent tab.

Shrines will level up the longer you train on a map and give increased bonuses the higher the level they are. You can improve the level up rate by upgrading the towers in Construction.

If you unlock the Shrine World Tour node in the Laboratory, a Shrine placed in town will make it's bonus apply to all maps of that world.

Unlock Shrine Speed from Gaming to level up +50% faster.

Obtain the Moai Head Artifact from Sailing for the following effect:

Get bonuses from all shrines from any map! You must be in same map/world to level them up though.

Obtain the Legend Talent Shrine World Order Bill for the following effect:

Introduces a bill to congress that will make Shrines gain EXP from AFK gains no matter what world you're in!

 

Tower Description Materials Max Level
Woodular
Woodular Shrine
This shrine increases the Total Damage of all characters on the same map. Level it up by claiming AFK Gains on the same map. 100
Health Shrine
Isaccian Shrine
This shrine increases the Max HP and Total Defense of characters on the same map. 100
Crystal Shrine
Crystal Shrine
This shrine increases the Shrine Level Up Rate for all other shrines on the same map. 100
Money Shrine
Pantheon Shrine
This shrine increases the Carry Capacity of all characters on the same map. 100
Clover Shrine
Clover Shrine
This shrine increases the Drop Rate of all characters on the same map. 100
Summereading
Summereading Shrine
This shrine increases all EXP gain for all characters on the same map. 100
Crescent Shrine
Crescent Shrine
This shrine increases Crystal and Giant Spawn chance, and Active EXP gain, of all characters on the same map. 100
Undead Shrine
Undead Shrine
This shrine increases the Respawn Rate of all monsters on the same map. 100
Primeordial Shrine
Primordial Shrine
This shrine increases the AFK Gain Rate of all characters on the same map. 100

Construction Boosts

Extra Boosts

These boosts can be earned from other areas of IdleOn.

Name Boost From
idleon boost Refinery Speed
Refinery Speed
+Refinery Speed [World 1]
Arcade
idleon boost Construction Build
Construction Build
+% Construction Build [World 1]
Arcade
% Faster Refinery Cycles [World 1]
Stamps
% Construction EXP [World 1]
Stamps
Taxidermied Cog Pouches +4 Cog Inventory slots. [World 1]
Stamps
% Building Speed [World 1]
Stamps
% Construction EXP [World 1]
Statues
idleon boost Buildie Sheepie
Buildie Sheepie
+% Construction SPD per POW 10 Sheepie Kills. [World 1]
The Upgrade Vault
SHINYFIN STEW +% Construction Build Rate, so you can hit all those boosted max levels you keep unlocking [World 2]
Alchemy
idleon boost CARPENTER
CARPENTER
+% Build Speed per Construction Level. Not affected by 'Warriors Rule' bubble. [World 2]
Alchemy
idleon boost Pipe Gauge
Pipe Gauge
Increases the speed of refinery cycles by +% [World 2]
Alchemy
VISIBLE INK +% Construction Exp gain. [World 2]
Alchemy
idleon boost CALL ME BOB
CALL ME BOB
+% Construction EXP Gain. Also gives +50% Bug-Fixing speed if your username is LavaFlame2. [World 2]
Alchemy
TURTLE TISANE +% Artifact find chance, Sigil SPD, Cooking SPD, and Construction Build rate. All MULTIPLICATIVE! A very special vial indeed... [World 2]
Alchemy
RED MALT +% Refinery Cycle Speed. I just want to see you squirm a bit more as you decide where to spend your precious salts hahahaha!! [World 2]
Alchemy
idleon boost Bonus Construction2
Bonus Construction2
Boosts Construction Build Rate and Construction EXP gain by +40% [World 2]
Bonus Ballot
idleon boost Bonus Construction
Bonus Construction
Boosts Refinery Cycle Speed by +50% [World 2]
Bonus Ballot
Refinery Cycle Complete 1 Refinery Cycle automatically [World 2]
Killroy's Slaughterhouse
+20% Build Speed [World 2]
Obols
+1% Build Speed [World 2]
Obols
+2% Build Speed [World 2]
Obols
+12% Build Speed [World 2]
Obols
+5% Build Speed [World 2]
Obols
idleon boost Construction Container
Construction Container
% Base Build Rate, % Shrine Charge Rate, % Construction EXP [World 2]
Post Office
Makes your flaggies unlock spaces faster, opening up your board for more cogs! Each purchase boosts Flaggy rate by +50% [World 3]
Gem Shop
Unlocks +1 more slot to build towers in! Remember, each slot builds at your FULL build rate, so this upgrade helps massively to upgrade all your towers to max level! [World 3]
Gem Shop
Each purchase gives you +4 cog inventory spaces, to store all your cogs in! [World 3]
Gem Shop
The Salt Lick (refinery) +% Refinery Speed for all cycle types. In other words, cycles take less time. [World 3]
The Salt Lick
These premium cogs are the best in the same! Yin Cogs have the best base stats! Yang Cogs have the best Surround Effects! Each purchase gives 1 of each! [World 4]
Gem Shop
idleon boost Gilded Cyclical Tubing
Gilded Cyclical Tubing
All refinery cycles occur 3x faster. Faster cycles means more salts! [World 4]
Laboratory
idleon boost Bored Bean
Bored Bean
+% Faster Refinery Speed [World 4]
Pet Breeding
idleon boost Demon Genie
Demon Genie
+% Faster Refinery Speed [World 4]
Pet Breeding
idleon boost Whale
Whale
+% Faster Refinery Speed [World 4]
Pet Breeding
idleon boost Construct Mastery
Construct Mastery
+1% Refinery Speed Per 10 Total Levels, +35 Max Level For Trapper Drone, +2% Damage Per 10 Total Levels Over 750, +100 Max Level for Talent Library in Construction, +5% Build Speed per 10 Total Levels Over 1,250, +100 Max Level For All Shrines, +30 Max Level for All Wizard Towers [World 4]
The Rift
idleon boost Skill Mastery (construction)
Skill Mastery (construction)
Level 150: +25% Construction EXP Gain Level 200: +15% Shrine Lv Up Rate Level 300: +5% Total Damage Level 400: +10% All Skill EXP Level 500: +5% All Skill Efficiency Level 750: +1% Printer Output Level 1000: +25% All Skill EXP [World 4]
The Rift
idleon boost Omniphau
Omniphau
When claiming non-candy AFK gains, also progress one of the following by the AFK time! (Refinery, 3D Printer, Cooking, Pet Breeding, Sailing, or Gaming) [World 5]
Divinity
Jewel Cogs Collect Ultimate Cogs while there are 5+ left to get a Jewel Cog (1/day) [World 5]
Gaming
idleon boost Penny and her Lane of Puffers
Penny and her Lane of Puffers
11.5x Construct SPD [World 6]
Summoning
idleon boost Rob and his Ice Cold Killer Snakes
Rob and his Ice Cold Killer Snakes
2.05x Construct SPD [World 6]
Summoning
idleon boost Grunkle and their Rooted Whimsy
Grunkle and their Rooted Whimsy
3.8x Construct SPD [World 6]
Summoning
idleon boost Giuseppe and his Power Tools
Giuseppe and his Power Tools
3.1x Construct SPD [World 6]
Summoning
idleon boost Inevitable Builder
Inevitable Builder
Gives 1 additional Trimmed Construction Slot, and makes them 1.75x faster for a total bonus speed of x! [World 7]
Legend Talents
idleon boost Cog Lover
Cog Lover
You can claim +2 more Jeweled Cogs every day, if you have them unlocked... [World 7]
Legend Talents
idleon boost More Soot More Salt
More Soot More Salt
Refinery cycles are 1.75x faster [World 7]
Legend Talents

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