The Barbarian King is an immortal unit, so he only has to be summoned once. However, if he is injured or falls in battle, he must regenerate his health by sleeping for a period of time before he can be used again. If you attack a village while its Barbarian King is still regenerating, the Altar will be empty.
The amount of time he sleeps to regenerate is directly proportional to the health he has lost by the end of the battle. If he is not damaged (or is fully healed before the battle ends), then he is ready to fight immediately; however, if he falls in battle or is wounded, then he must sleep for some time to regenerate.
The more the Barbarian King is upgraded, the more time it will take to fully regenerate his health.
The Barbarian King sleeps during the time it takes to upgrade along with the normal costs (a free Builder, Dark Elixir and time).
You can temporarily quadruple the hero's healing rate for 1 hour by spending 5 Gems.
The Barbarian King now only defends his territory around his platform and will retreat if lured too far out.
Starting at level 5, the Barbarian King obtains an ability called Iron Fist which can be used on the battlefield. It partially heals him, summons up to twenty additional Barbarians and grants the Barbarian King and any surrounding Barbarians increased damage and speed. This does not stack with the Rage Spell, and does not affect any other troops except the Barbarian King and nearby (friendly) Barbarians. This ability gets more powerful every fifth level.
When attacking, he can be deployed just like any other unit. When he is damaged, he must sleep to recharge before he can be used again. The regeneration time is directly proportional to how much health he must recover. He may be instantly brought up to full health with Gems.
He is best used with Healer and Archer support. Barbarians are also excellent support troops because they will also be affected by his Iron Fist ability if they are nearby when it is activated (unlike the Archer Queen where she can't affect Archers).
He is also good for helping to destroy the remaining buildings of a village after most or all defenses have been destroyed.
The Barbarian King can be easily swarmed by a group of Archers or Barbarians as he only attacks one target at a time and has slow attack speed.
If your army strategy uses Barbarians, try to use Iron Fist when there are some nearby. When they are close, activate your Iron Fist to make the most out of it.
As the Iron Fist ability recovers some health, you should let your Barbarian King take some damage before activating this ability to maximize the recovered health provided by activating the ability.
The Barbarian King has two modes: he can be set to "Sleep", which will put him to sleep on his Altar and cause him to ignore any attacks to your village, or "Guard", which will put him on patrol around your base and cause him to engage any enemy Troops that come within his targeting range during a defensive battle. In "Sleep" mode he will not appear on the battlefield at all.
Though he is very strong on offense, he only attacks one target at a time on defense which makes him easy to kill with multiple units.
It is a good idea to place the Altar in the middle of a group of storages or other areas you wish to protect.
Unlike troops in the Clan Castle, the Barbarian King cannot be lured to the edge of the map and then destroyed out of range of the defenses (unless his Altar is near the edge). If his target moves out of his patrol area, he will retreat and engage another enemy inside his patrol area. If no enemies remain in his patrol area, he will resume patrolling.
The Barbarian King goes through visual changes at levels 10 and 20.
Initially, the Barbarian King is similar to a giant Barbarian, with a steel crown, steel gauntlet, and steel shoulder guard. He uses a blunt sword with a stone hilt.
At level 10, his gauntlet changes from steel to gold.
At level 20, his shoulder guard's edge turns gold, and the central spike turns gold as well.
The Barbarian King only holds his sword in his right hand when he is turned toward to the right sides of the village (toward the back right corner, the front right corner or directly toward the right side). When the King turns and faces to the left he is rendered in mirror image, causing his sword and gauntlet/shoulder guard to switch arms. This is done ostensibly to save graphics space.
If you move the Barbarian King Altar while the King is sleeping on it, he will get up and walk to his altar, then sleep again.
The Barbarian King can be healed by Healing Spell or a Healer while battling; however, this healing occurs at 50% of the rate of that of normal troops.
Every slash he makes on a building or unit creates a mini explosion.
When you tap on him he will yell a low pitched battle cry and stand still for a moment, similar to the Archer Queen.
When the Barbarian King is completely healed, a jingle will play, like the Archer Queen.
When the Barbarian King 'falls' in battle, an explosion occurs and a bright beam of light is sent up into the sky temporarily. He is then seen standing dazed with stars flying around his head for the remainder of the battle.
Each successive upgrade of the Barbarian King adds approximately 2.5% health and 2% damage, but also adds a constant one minute to his total regeneration time. As a consequence, the Barbarian King's regeneration rate changes as he levels up. Initially the Barbarian King's regeneration rate slows down each level, going from 10,200 hit points per hour at level 1 to 5,347.5 per hour at level 31. Beyond level 31 the rate begins to slowly climb again, eventually reaching 5,452.7 hit points per hour at level 40.
The recovery time no longer caps at level 30; the 1 minute added to the regeneration time is applied to all levels.
The Barbarian King will wander in circles around his Altar, occasionally seen jumping over walls as well.
The Barbarian King is basically the counterpart of the Archer Queen, and vice versa. The Barbarian King is the tank specialist, while the Archer Queen is the damage specialist, with the Grand Warden as the support specialist.
Once the Barbarian King is deployed, his icon in the troop deployment window becomes the activation method for Iron Fist. Simply click on his icon again and Iron Fist will be activated but this only applies to Heroes that are level 5 and above.
When the Iron Fist is activated the Barbarian King gains a temporary Rage Spell-like effect around him, except smaller and it only affects himself and Barbarians.
The 3rd July 2014 update reduced the effect of the Rage Spell on the King by 20%.
The 16th September 2014 update has halved the regeneration time relative to before that update (up to level 30).
While attacking, if your opponent's Barbarian King Altar is empty and the King wakes up during your battle, the Altar will sparkle like he is waking but there will be no Barbarian King to defend the base.
If your Barbarian King wakes up while you are in Village Edit Mode, a sparkle will appear wherever the Altar originally was (even if you moved it already).
If the Barbarian King falls while his ability is still active, the ability's aura will remain until the moment it is supposed to expire; however any nearby Barbarians will no longer be enraged by the ability.
The Barbarian King will alternate between hitting the building with the sword and his fist.
Although swarms of troops are effective against the Barbarian King, the P.E.K.K.A is also effective for taking down low level Barbarian Kings.