"Your troops are stationed in Army Camps. Build more camps and upgrade them to muster a powerful army."
The Army Camps is where your troops go when they're done training. Most troops will take up more than one space (Barbarians, Archers, and Goblins do only take up one space though). Upgrading and building more Army Camps allow more troops to be stored, allowing higher chances of victory in raids.
They continue to function even when they are being upgraded, allowing you to keep your armies at full capacity at all times.
Unlike Clan Castle troops, troops stationed in the Army Camp do not defend your village during an attack. In fact, they do not appear on the attacker's map at all (all Army Camps, full or not, will appear empty to an attacker).
Prior to the Halloween 2012 update, troops would die/disappear if their Army Camp was destroyed in a raid. In the update, troops were allowed to remain even if their camp was destroyed. Due to widespread player support towards keeping this feature, Supercell made it permanent. As a result, troops stationed in Army Camps are no longer at risk if their camp is destroyed by an attacker.
The maximum amount of housing space you can have for your Troops is 280 (4 Army Camps x 70 spaces). This increases to 320 if you include the extra 40 in a fully upgraded Clan Castle at Town Hall 12.
Heroes do not use Army Camps. They instead use their respective Altars.
You should not surround your Army Camps with Walls, as they do not need protecting. Also, the Army Camps occupy a lot of space (4 x 4). More walls are needed to contain them when the extra walls can be used to surround defensive buildings that are already inside the wall, strengthening the defense.
It is always preferable to initially build all available Army Camps, and then upgrade the lowest-level ones first. Every time you upgrade (except upgrading to level 2) the camp only gains 5 more housing space and it costs more elixir the more you upgrade. The next level is usually much more expensive than the one before it.
Army Camps have a unique hitbox, unlike other Buildings. That means that attacking Troops will have to walk right to the center where the campfire is located in order to attack the Army Camp.
Clan Castletroops do not go into the Army Camp when donated and thus do not take housing space in the Army Camp; they instead go to the Clan Castle.
If you look closely, you can see reactions from some Troops when you tap on the Army Camp. For example, Barbarians raise their swords, Archers pump their fists in the air and Minions sneeze.
As of the 16 September 2014 update, you can now dismiss any troops from the Army Camps, but the troop cost is not refunded.
The Army Camp undergoes significant visual changes at levels 7 and 10.
When initially constructed, the Army Camp is a large open grassy area with a cooking fire in the center.
At level 2, a bare spit appears over the fire, and the fire appears to be larger.
At level 3, a carrot appears on the spit.
At level 4, the carrot is replaced with a chicken/turkey. A bone is sticking out.
At level 5, the chicken/turkey is replaced with a pig.
At level 6, the pig is replaced with a bull and more rocks are added around the fire. The bull has a ring in its nose, and it is a dark reddish brown color.
At level 7, the spit and food disappear. Instead, the cooking fire is surrounded by large black rocks with sharp edges.
At level 8, the black rocks glow bright red and it has a slight glow around the rocks. The rock on the far right shrinks in size. It suggests that the rocks have been burned. There also appear to be more jagged rocks surrounding the fire.
At level 9, the glowing black rocks change their position and size to be more uniform; all being very similar in size and having 3 rocks on each end. 6 sets of bars are also added above the fire, 3 going horizontal and 3 going vertical.
At level 10, the glowing black rocks are removed, and instead the campfire rests atop a stone platform, with metallic corner pieces on each corner, each with a decorative golden ring. The campfire is surrounded by flat stones that cover a significant portion of the grass around the Army Camp.
There's a special kind of Army Camp in the Goblin Gauntlet mission in Single Player Campaign that only consists of a camp fire with different surroundings that the one in the Army Camp, which is only 2 by 2. You can notice this by the other obstacles that are next to the camp fire. You can also drop troops over it since it is considered as an obstacle. Another special Army Camp appears in the Maginot Line single player mission, also as an object but level 7.
When you move your Army Camp, any Troops there will wait until it is placed in its new position, at which time they will move towards the place where you put it.
When a Troop finishes training, smoke appears in the Army Camp that the Troop will go to.
When your Army Camps are full they will display a full sign on top. However you can't see this sign when upgrading the Army Camp, because it is replaced by the building upgrade's progress bar.
The housing spaces of Army Camps are calculated jointly rather than individually. For example, a player who has 4 level 6 Army Camps will be able to hold 10 Dragons even though each individual Army Camp has 50 housing spaces. As a result, two of the four Army Camps will appear to hold 3 Dragons that it can't hold individually.
Tapping this icon displays information about the Army Camp/Home Village, such as Level, Total Troop Capacity and Hitpoints.
Tapping this icon begins upgrading the Army Camp/Home Village to the next level, if you have enough resources and a free Builder. When the Army Camp/Home Village is at maximum level, this icon is not shown.
Tapping this icon instantly upgrades the Army Camp/Home Village to the next level, at the cost of one Hammer of Building if you have one. When the Army Camp/Home Village is at maximum level, this icon is not shown.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of the displayed number of Gems.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of one Book of Building. This icon is only shown if you have at least one Book of Building.
Tapping this icon, which is displayed only while an upgrade is in progress, boosts all your Builders for 1 hour by a factor of ten, at the cost of one Builder Potion. This icon is only shown if you have at least one Builder Potion.
Tapping this icon, which is displayed only while an upgrade is in progress, cancels the current upgrade and refunds half of the upgrade cost.
Tapping this icon opens up the troop training interface, allowing you to train troops.