Read my General BH advice before reading this.
You want to rush asap in this section of the game. The earlier you rush, the faster you gain loot, the faster you progress and the stronger you become. Rushing quickly becomes a strong positive feedback loop which allows you to snowball your advantage.
The in-game tutorial will bring you to BH2 immediately which is where my guide will start. You start out with a few buildings already placed to help you out.
BH2 upgrade priority guide:
Unlike the main base guide, this will show the direct path to the builder hall upgrade. All the upgrades below are to be done as soon as you have the resources to do so. You may need to skip some upgrades to do something lower down if you don’t have enough resources.
Barbarians are the strongest and quickest troops to upgrade, so they will be prioritized over everything else. The builder base really exemplifies the fact that one strong, high-level troop is far superior to having 10 low-level troops. Don’t be worried that your lab is idle most of the time, resources are the limiting factor here, not time.
- Army camp. This is the most important upgrade you can get right now, it doubles your army strength.
- Star lab lvl1. You probably won’t have enough elixir to build this so early, but do build it as soon as you have the elixir to do so.
- Barbarians lvl2. Do this as soon as you farm enough elixir.
- Star lab lvl2, so that you can upgrade your barbarians further.
- (optional) Barbarians lvl3 and lvl4. Do this whenever you have extra elixir. Don’t worry about upgrading your BH before this is done.
- New push trap. Cheap upgrade.
- New archer tower. You must have this to upgrade your BH
- New double cannon. You must have this to upgrade your BH.
- New wall segments. This costs 16k and doesn’t give you much, that’s why its the last upgrade before your builder hall.
- Builder hall lvl3. You can reach BH3 within the first day of playing
Builder hall lvl3:
Calculating the marginal cost, it seems like getting your 3rd army camp is probably more efficient than upgrading barbs to lvl6 because the former takes less resources and time to complete. Of course, both should be maxed before going to BH4.
3rd army camp: costs 180k elixir + 3 hours to get 18 barbs, but you need to upgrade elixir storage to lvl2
Barbs lvl6: costs 50+50+100k elixir + 9.5 hours (star lab and barb upgrades) to get 20 barbs, you don’t need to build elixir storage
- Star lab to lvl3. This will allow you spend your elixir meaningfully
- Elixir storage lvl1. This allows better management of resources
- New lvl1 walls, new lvl1 cannon, new spring traps and new mines. These are cheap upgrades which will increase your defensive strength quickly.
- Barbarians lvl5 and lvl6. This is an important upgrade because it will allow you have 20 barbarians in your raids. This would greatly increase your strength
- Gold and elixir collectors to lvl3. Besides daily loot, upgrading your collectors is the only way you can earn more loot. The earlier you upgrade these, the more loot you accrue in the long run.
- Elixir storage lvl2, a must if you want to have 50% more troops in your army.
- Firecracker lvl1, do this while farming 180k elixir for the army camp
- Tesla lvl1, do this while farming 180k elixir for the army camp
- 3rd army camp. Finally, you can bring 30 barbarians in your army, go for it!
- Crusher lvl1. This would greatly improve your defense so that you can stop other players using barbarians. When you’re attacking, don’t spam all your barbarians early in the raid. You want to stagger them so that they can overpower the crusher without being destroyed in one fell swoop.
- Gold storage lvl2. You must have this in order to upgrade your builder hall.
- (optional) while farming the necessary gold for the builder hall upgrade, you can upgrade your barracks a few times.
- Builder hall lvl4, on to level 4!
You’ll notice that I’m neglecting the gem mine for BH3. At this level, it is not worth it for its return. 120k elixir is better spent elsewhere, especially because trees provide more gems them the mine itself!
Builder hall lvl4:
This time, upgrading barbarians don’t increase their numbers so they are a lower priority. You need to build your 4th army camp so that you can bring 33% more barbarians in your raids.
You also unlock the clock tower which is a relatively powerful building which can dramatically speed up your progress. You can activate it 3 times per day to save up to 3.5 hours per day at BH9. At this level though, only lvl1-2 is cost efficient. You can upgrade it later because its marginal benefit becomes minuscule compared to its cost.
- Save up 200k gold so that you can upgrade your elixir storage to lvl3 immediately and start saving up for your 4th army camp.
- Advanced tip: if you don’t have 200k gold, calculate how much gold you can earn in the next loot cycle. Spend excess gold on the mega mine, normal mine, push trap and archer tower such that you can still afford the gold mine upgrade within the next loot cycle.
- Example, if you have 165k gold and you are about to get 70k in the next cycle. Spend 30k on the mega mine and 1k on the push trap. Wait till the next cycle and spend 200k gold to upgrade your elixir storage.
- Fourth army camp. You may not be able to afford it immediately, but do buy it as soon as you have 350k elixir.
- New walls, mega mine, normal mine, push trap and archer tower. Quick upgrades which can increase your strength immediately.
- Elixir collector to lvl4. The earlier you upgrade this, the more loot you get in the long run.
- Rebuild your clock tower. This would give you a decent 3 minute worth of boost. Its small, but it will add up.
- After army camp is done, upgrade your gold mine to lvl4.
- Gold storage lvl3. This costs elixir, but I cannot find anywhere else to put it. You will need this for some upgrades down the line.
After completing the above upgrades, all the below upgrades can be done in any order you like as long as you can afford it. They are all relatively the same in terms of importance and strength.
- Star lab lvl4. You need this to upgrade to unlock lvl8 barbarians
- Guard post lvl1. This is an amazing defense which will distract enemy troops, one of the strongest defenses in the game.
- Clock tower lvl2. You can probably upgrade this before you afford your star lab upgrade.
- Air bombs lvl1. This will allow you to stop pesky minion attacks very well.
- Once star lab is done, its time to save up another 300k elixir + 330k elixir to upgrade barbarians to lvl8.
- Gold storage lvl4. This will be the final upgrade before you can afford the BH5 upgrade. Do
- Technically you don’t need to upgrade elixir storage because barbarians don’t require the full storage. But if you don’t upgrade it, you may overflow with elixir while you are waiting for the 2 day long BH5 upgrade.
- Builder hall to lvl5
All in all, everything above can be done in 1-2 weeks which is really fast. BH5-6 doesn’t really unlock a lot so you can choose to skip ahead really quickly in the following section.