To unlock a new troop you only need a single Barrack upgraded.
#COC BUILDER TH10 DEFENCE UPGRADE#
However, it's not really necessary to upgrade all your Barracks.
Unlocking new troops also helps to make the game fresh, so go for it. Barracks upgrades depend on your level and which troop you will unlock, but overall it's a great idea to unlock new troops right away so you can start upgrading them on the Laboratory. Now it's time to make room to more troops on your camps and unlock new troops and spells. Clan Castle, Barracks, Army Camp, Spell Factory Maxing out all troops and spells on the Laboratory is quite hard and even maxed TH 12 players struggle to finish everything, so keep it working all the time. However, the most important thing is to keep your Laboratory always busy, never let it stop, always research something. The laboratory is a great upgrade so you can upgrade your favorite troop as soon as possible. Storages are a very important upgrade for two reasons: bigger storages are necessary for certain upgrades and it's important to have more space to hold resources when all builders are busy. So don't waste any time and go for it! 2. If you have maxed Heroes you own the game and can attack any village regardless of defenses or base layout. It's more important than any defense or regular troop. Heroes are the most important upgrade in the game. If you are skipping wars to upgrade your Heroes, upgrade all of them at the same time. Why? It takes over 280 days to reach level 60 King or Queen, so the sooner you start, the better. Other defenses: below TH11 first Splash Damage defenses, above first Single Target defenses.Clan Castle, Barracks, Army Camp, Spell Factory.It's a list that will give you some challenges but will not make let the game being too slow and frustrating. There are many different approaches on this game, but on this list I will share an aggressive upgrade order so you can progress on the game fast and don't spend too much time stuck on a Town Hall level. On this tutorial I will share my Upgrade Priorities list. Making errors could cost you a lot of time and resources and be very frustrating. Upgrading your buildings and defenses on the right order is extremely important on Clash of Clans and severely affects the gameplay.
For the Builder Base, please visit the Builder Base Upgrade Priorities article.