Updated for Town Hall 18 (October 2026).
The O.T.T.O Hut is now called B.O.B Control. It is a Builder Hall 9 building in the Builder Base with four tasks attached, and finishing all four gives your Home Village a permanent sixth Builder named B.O.B. O.T.T.O did not disappear: since May 2023 he works on the Builder Base side as its second Builder.
What happened to the O.T.T.O Hut (May 15, 2023)
Builder Base 2.0 rebuilt the O.T.T.O system. Before the update, completing the O.T.T.O Hut activated the O.T.T.O robot on the Builder Base and freed the Master Builder to move into the Master Builder’s Hut as an extra Home Village Builder. After the update:
- The O.T.T.O Hut was renamed B.O.B Control and given a new, looser set of tasks.
- Finishing it now unlocks B.O.B’s Hut in the Home Village, which replaced the Master Builder’s Hut. B.O.B stays there for good.
- O.T.T.O moved into O.T.T.O’s Outpost, the hall of Stage 2, and becomes the Builder Base’s second Builder at Builder Hall 6. The Master Builder stays on the Builder Base as its main Builder.
- Players who had already unlocked O.T.T.O got B.O.B right away and kept their finished building.
B.O.B Control requirements
You can place B.O.B Control once you reach Builder Hall 9. Building it costs 100,000 Builder Gold and finishes instantly. After that, each level costs nothing and takes no time; you just need the matching task done and a free Builder Base Builder to tap the upgrade. The tasks go in order, one per level.
| To reach | Task | What it takes in practice |
|---|---|---|
| Level 2 | Gear Up all 3 Home Village buildings: Cannon, Archer Tower and Mortar | Home Village: Cannon level 7, Archer Tower level 10, Mortar level 8. Builder Base: Double Cannon level 4, Archer Tower level 6, Multi Mortar level 8. |
| Level 3 | Upgrade any Builder Base troop to level 18 | Star Laboratory level 9 (Builder Hall 9) |
| Level 4 | Upgrade any Builder Base defense to level 9 | Builder Hall 9. O.T.T.O’s Outpost, traps and Walls do not count. |
| Level 5 | Battle Machine and Battle Copter at a combined level of 45 | The Battle Copter starts at level 15 when you buy it, so this is less than it sounds. |
The building itself is a 2×2 hut with 250 hitpoints. It sits in Stage 2 of your Builder Base and has no attack, so on defense it is just something for the attacker to knock down.
Old O.T.T.O Hut tasks compared with now
Most of the search traffic for “O.T.T.O Hut requirements” is looking for the old list. Here is what changed:
| Step | O.T.T.O Hut (June 2019 to May 2023) | B.O.B Control (May 2023 onward) |
|---|---|---|
| 1 | Gear Up Cannon, Archer Tower and Mortar | Same |
| 2 | Cannon Cart to level 18 | Any troop to level 18 |
| 3 | Mega Tesla to level 9 | Any defense to level 9 |
| 4 | Battle Machine to level 30 | Battle Machine plus Battle Copter totaling 45 |
The old tasks could be done in any order. The new ones are checked in sequence.
Fastest route to B.O.B
- Start the Mortar gear-up last, and early. It is the longest gear-up, and the task only checks that the gear-up has started, so you can level up B.O.B Control while it is still running. The Mortar requirement also means Town Hall 10 is the earliest point you can finish.
- For the level 18 troop, pick a troop you spam. The Baby Dragon is the common choice because it unlocks earlier than the Night Witch and one upgraded slot carries a whole army. Research happens in the Star Laboratory.
- For the level 9 defense, use the Multi Mortar. You already need it at level 8 for the Mortar gear-up, so it is one upgrade away.
- Spend most of your Builder Elixir and any Hammers or Books of Heroes on the Battle Machine and Battle Copter. The 45-level hero total is usually the last task to fall.
One known trap: in February 2025, merging a geared-up Cannon and Archer Tower into a Multi-Gear Tower made the gear-up task impossible to complete. Supercell fixed it in the March 2025 update, so merging is safe now.
Builders on each side after the change
The Home Village gets B.O.B as a sixth Builder that lives in B.O.B’s Hut. Unlike the five regular Builder’s Huts, B.O.B’s Hut cannot be upgraded, so it never gets a weapon. On the Builder Base you have the Master Builder from the start, O.T.T.O from Builder Hall 6, and since May 26, 2026 an extra Builder sold in the shop from Builder Hall 2. Supercell’s notes say that extra Builder needs all Home Village Builders unlocked first.
FAQ
Where is the O.T.T.O Hut in Clash of Clans?
It is the same building under a new name, B.O.B Control, in Stage 2 of your Builder Base. If you finished the O.T.T.O Hut before May 15, 2023, yours is already maxed and B.O.B is already working in your Home Village.
What are the O.T.T.O Hut requirements now?
Builder Hall 9, then: gear up the Cannon, Archer Tower and Mortar; get any troop to level 18; get any defense to level 9; get your two Builder Base heroes to a combined level of 45.
Can the Master Builder still go to the Home Village?
Not as a sixth Builder. That job belongs to B.O.B now. The Master Builder still handles the three Home Village gear-ups, and each one needs a free Builder on the Builder Base.
Sources: Supercell, Builder Base 2.0 full patch notes (May 15, 2023); Supercell, May Update notes (May 26, 2026); in-game data. Checked October 1, 2026.
