Getting a 6th builder in Clash of Clans is one of the most impactful long-term upgrades you can make — a permanent extra worker who speeds up every queue in your Home Village, completely free of Gems. The process revolves around the O.T.T.O Hut in the Builder Base: build it, complete four upgrade tasks, and the robot known as O.T.T.O crosses over to your Home Village as a tireless 6th builder.
What you need before you start
The 6th builder is a mid-to-late-game reward. You need a Builder Hall level 9 in the Builder Base (which also requires a Town Hall level 10 or higher in your Home Village) before the O.T.T.O Hut appears in the Builder Base shop. If you are still climbing through early Builder Hall levels, focus on upgrading your Builder Hall and its defenses — the path will open naturally. Once you hit BH9, the steps below take you to the finish line.
How to get a 6th builder in Clash of Clans
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Step 1: Reach Builder Hall 9
Open Clash of Clans and travel to the Builder Base by tapping the Boat on the shore of your Home Village. Work through the Builder Base upgrade path until your Builder Hall reaches level 9. This unlocks the O.T.T.O Hut in the Builder Base shop and is a hard requirement — the hut simply does not appear until BH9 is achieved. Your Home Village Town Hall must be at least level 10 as well, since the two progress tracks are linked.
Builder Hall 9 is the gateway to the O.T.T.O Hut and the 6th builder. -
Step 2: Build the O.T.T.O Hut
Once you have Builder Hall 9, go to the Builder Base Shop and place the O.T.T.O Hut. This building is the quest hub for the entire 6th-builder unlock. Tap the hut after construction to see the four tasks you need to complete. Each finished task automatically upgrades the O.T.T.O Hut by one level, moving you closer to level 5 — the level at which O.T.T.O is fully repaired and ready to move to your Home Village.
Build and tap the O.T.T.O Hut to reveal the four unlock tasks. -
Step 3: Review the four O.T.T.O tasks
Inside the O.T.T.O Hut you will find four tasks, each representing a specific upgrade goal. The tasks are: Gear Up three Home Village defenses (Cannon to level 7, Archer Tower to level 10, Mortar to level 8), upgrade the Cannon Cart to level 18, upgrade the Mega Tesla to level 9, and upgrade the Battle Machine hero to level 30. You can complete these in any order. Tap the O.T.T.O Hut at any time to check progress.
All four tasks must be completed to unlock O.T.T.O as your 6th builder. -
Step 4: Gear Up three Home Village defenses
The Gear Up mechanic lets the Master Builder in the Builder Base travel to your Home Village and upgrade a compatible defense. To satisfy this task you need to Gear Up three different buildings: the Cannon (requires Cannon level 7 in the Home Village and Cannon level 4 in the Builder Base), the Archer Tower (Home Village level 10, Builder Base level 6), and the Mortar (Home Village level 8, Builder Base level 6). Open each defense in the Home Village and tap Gear Up when it appears. Each Gear Up sends the Master Builder away temporarily, so stagger them to avoid blocking your Builder Base queue.
Gear Up the Cannon (Lv 7), Archer Tower (Lv 10), and Mortar (Lv 8) in your Home Village. -
Step 5: Upgrade the Cannon Cart and Mega Tesla
The Cannon Cart is a Builder Base troop that must be upgraded to level 18 (its maximum). The Mega Tesla is a Builder Base defense that must reach level 9. Both upgrades use Builder Gold, so focus your Builder Base loot on these two while you also chip away at Gear Ups. The Cannon Cart upgrades in the Builder Barracks; the Mega Tesla upgrades directly on the map. These are time-intensive upgrades, so start them as early as possible once the O.T.T.O Hut is placed.
Max out the Cannon Cart (level 18) and Mega Tesla (level 9) to tick off two of the four tasks. -
Step 6: Upgrade the Battle Machine to level 30
The Battle Machine is the Builder Base hero and must reach level 30. He upgrades using Builder Elixir and sleeps for a fixed time after each level, so keep his upgrades queued consistently. At level 30 — and once the other three tasks are also complete — the O.T.T.O Hut upgrades to level 5. O.T.T.O is now active in your Home Village as the permanent 6th builder, working independently around the clock alongside your five original builders.
Once the Battle Machine hits level 30, O.T.T.O becomes your permanent 6th builder in the Home Village.
Tips to speed up the process
- Parallel everything. There is no set order for the four tasks. Start Gear Ups and Cannon Cart / Mega Tesla upgrades simultaneously so nothing sits idle.
- Do not neglect Builder Base attacks. The Versus Battle (or Builder Base 2.0 mode) is your primary source of Builder Gold and Builder Elixir. Attacking twice per day keeps your coffers full.
- Use Season Pass boosts. The Gold Pass cuts upgrade times across both villages, including the Battle Machine — well worth it if you want to reach level 30 faster.
- Gear Ups are one-time only. Once you Gear Up a Cannon, it stays Geared Up permanently. You do not need three Cannons — one Cannon, one Archer Tower, and one Mortar suffice.
- O.T.T.O stays even if you sell the O.T.T.O Hut. The 6th builder is permanently unlocked once the quest is complete — deleting the O.T.T.O Hut later does not remove him.
Troubleshooting
The O.T.T.O Hut is not appearing in my shop
The hut only shows up after you upgrade your Builder Hall to level 9. Check your current Builder Hall level by tapping the hall on your Builder Base map. If it is lower than 9, continue upgrading Builder Base buildings to reach that milestone.
The Gear Up button is greyed out
Gear Up requires the Home Village defense and the equivalent Builder Base building to both be at the required levels. Tap the building and look at the Gear Up tooltip — it will show which level requirement is still unmet. Also ensure the Master Builder is free (not away on a Gear Up job somewhere else).
I completed all four tasks but O.T.T.O has not appeared
All four tasks must be finished simultaneously. Tap the O.T.T.O Hut and verify that every checkbox shows a green tick. If one task is still in progress, wait for it to complete — O.T.T.O appears automatically once the hut reaches level 5.
Frequently asked questions
Is the 6th builder free in Clash of Clans?
Yes. O.T.T.O is completely free to unlock — you do not spend any Gems. The cost is time and in-game resources used to reach Builder Hall 9 and complete the four O.T.T.O tasks. The only alternative is buying builders with Gems, but O.T.T.O is obtained through gameplay alone.
How long does it take to get the 6th builder?
It varies widely depending on your progress, how active you are, and whether you use time boosters. Reaching Builder Hall 9 alone can take several months for a new player. Once the O.T.T.O Hut is built, completing all four tasks typically adds a few more months. Using the Gold Pass noticeably shortens upgrade timers.
Can I get the 6th builder without spending money?
Absolutely. Every step of the process uses in-game resources earned through normal play. Spending real money on the Gold Pass or Gems speeds things up, but it is not required. Many free-to-play players have unlocked O.T.T.O purely through consistent daily attacks and patient upgrading.
Does O.T.T.O work in the Home Village or the Builder Base?
Once unlocked, O.T.T.O works exclusively in your Home Village. The Master Builder (who lives in the Builder Base) is a separate character. You still have your regular Master Builder for Builder Base upgrades, and O.T.T.O joins the five original builders in the Home Village.
What is the Battle Machine max level for the 6th builder unlock?
The Battle Machine must reach level 30 to satisfy the O.T.T.O task. As of 2026, the Battle Machine's level cap is higher than 30, but level 30 is all that is needed to unlock the 6th builder.
Final thoughts
Unlocking the 6th builder in Clash of Clans is a long journey, but it is among the best investments you can make in the game. A permanent extra builder in your Home Village compresses upgrade timelines for years to come. Focus on Builder Hall 9, place the O.T.T.O Hut as soon as it is available, and chip away at the four tasks in parallel. For official game updates and news, visit the official Clash of Clans page on Supercell.com.
