Updated for Town Hall 18 (October 2026).
The Mega Mine is the Builder Base’s heaviest trap: a hidden 2×2 barrel that you set to either ground or air mode, and that blows up for 250 damage at level 1 and 550 at level 10. It unlocks at Builder Hall 4, you can have up to four by Builder Hall 9, and one in the right spot can wreck a Night Witch or Baby Dragon attack on its own.
How the Mega Mine works
It plays the same role as the Giant Bomb in the Home Village, with one big difference: you pick what it hunts. Tap it in your base and switch between ground mode and air mode. In air mode it hangs in the air from two chains; in ground mode it sits on the ground.
- Triggers when an enemy of the chosen type comes within 3 tiles.
- Explodes over a 4-tile radius, so it also hits troops farther out than the one that set it off.
- Since Builder Base 2.0, it needs a minimum spring weight of 3 to trigger, so a single Drop Ship skeleton walking past will not set it off.
- Like every Builder Base trap, it resets itself after each battle.
Mega Mine levels
| Level | Builder Hall needed | Damage | Cost (Builder Gold) | Upgrade time |
|---|---|---|---|---|
| 1 | 4 | 250 | 30,000 | None |
| 2 | 4 | 275 | 40,000 | 1h |
| 3 | 4 | 300 | 50,000 | 3h |
| 4 | 4 | 330 | 80,000 | 6h |
| 5 | 5 | 360 | 120,000 | 12h |
| 6 | 6 | 395 | 300,000 | 1d |
| 7 | 7 | 430 | 600,000 | 1d 12h |
| 8 | 8 | 470 | 1,000,000 | 2d |
| 9 | 9 | 510 | 1,400,000 | 3d |
| 10 | 10 | 550 | 2,500,000 | 4d |
Number of Mega Mines: 1 at Builder Hall 4, 2 at BH6, 3 at BH8 and 4 at BH9.
Ground mode or air mode?
Pick the mode based on what you get attacked with most.
- Air mode shuts down Baby Dragons and packs of Beta Minions. It works best placed near your Firecrackers and Air Bombs, since those are what air armies go after first.
- Ground mode punishes Night Witches. When the Mega Mine’s level is at least half the Night Witch’s level, one blast can kill her outright (level 18 Night Witches are the exception). It also cripples Boxer Giants and wipes Raged Barbarians.
- If Night Witches are common at your trophy range, a good split is Mega Mines on ground and regular Mines on air, so the small Mines clean up the bats.
Where to place Mega Mines
Put them inside the base. On the outskirts, a cheap troop sets them off and the damage is wasted; deeper in, the explosion lands on the tanks and the support crowding behind them.
A riskier trick against Night Witches: many attackers drop their Night Witches in a corner so the bats can stack up. A ground Mega Mine in that corner can kill most of them before the attack starts. Careful players send the Battle Machine in first to check, so this does not always work.
Keep Push Traps away from your Mega Mines. A push can carry troops out of the blast radius before the mine goes off.
How to deal with Mega Mines when attacking
- Set them off on purpose with something cheap or tough. The Battle Machine is a good pick, since its Electric Hammer ability heals back the damage.
- You can trigger a mine on the other side of a wall by dropping a troop within its 3-tile trigger range. That is the cleanest way to clear one hidden inside the base.
- Look for empty 2×2 gaps in the base. They often hold a Mega Mine or a Hidden Tesla.
- Remember the blast reaches 4 tiles, wider than the trigger range. Keep your support troops a little behind whatever goes first.
Mega Mine changes since Builder Base 2.0
- May 15, 2023: level 10 added with Builder Hall 10; minimum spring weight to trigger raised to 3.
- October 20, 2023: damage cut at levels 3 to 10. Level 10 went from 620 to 550, and level 9 from 555 to 510.
- April 27, 2026: Hammer of Building can now be used on Builder Base traps.
The Builder Base guide explains how traps are shared between Stage 1 and Stage 2 (12 per stage at Builder Hall 10).
Mega Mine FAQ
Can a Mega Mine hit both air and ground?
No. It hits whichever one you set it to. You switch the mode by tapping it in your base.
How much damage does a max Mega Mine do?
550 at level 10, after the October 2023 damage reduction.
Why didn’t my Mega Mine go off?
Either it was set to the other mode, or the troops in range were too light. Since May 2023 it needs a spring weight of at least 3 to trigger.
Sources: Supercell release notes (Builder Base 2.0 full patch notes (Supercell, May 15, 2023)) and in-game data.
