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 left at 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.
You can temporarily quadruple the hero's healing rate for 2 hours by spending 10 Gems.
When attacking, he can be deployed just like any other unit. When his health is lowered 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 also good for helping to destroy the 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.
Many players place a few troops in the Barbarian King's radius to lure him out, and then use a group of Archers or Barbarians to attack him.
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.
The Heroes' upgrade cost, regeneration time and damage against Walls were changed in the May 2013 Update.
Sometimes, when the Barbarian King turns, his shoulder guard appear on his other arm, and his sword appears on the opposite arm as well.
If you move the Barbarian King altar when he is sleeping, he will get up and walks to his altar, then sleeps again.
Pulse of waves can be seen when the Barbarian King is awake after fully regenerating his health.
The Barbarian King can be healed by Healing Spell or 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.
Upgrading the Barbarian King's level requires a builder.
When you tap on him he will yell and stand still for a moment.
Tap on the Barbarian King (not his Altar) to view his attack radius, as the Barbarian King "patrols" his area moving constantly.
When he '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 for the remainder of the battle.
If a level 40 Barbarian King is used with a level 5 Rage Spell, it will destroy a level 10 Town Hall in 4 seconds.
While the Barbarian King is being upgraded you can't use him on the battlefield.
Each successive upgrade of the Barbarian King (up to level 30) adds approximately 4% health and damage, but also adds a constant four minutes to the total regeneration time. As a consequence, the Barbarian King's regeneration rate changes as it levels up. Initially the Barbarian King's regeneration rate slows down each level, going from 1,500 hit points per hour at level 1 to 1,332 per hour at level 11. Beyond level 11 the rate begins to climb again, eventually reaching 1,500 hit points per hour again at level 26, and 1,595 at level 30.
Beyond level 30, the Barbarian King gains additional health and damage at each level (approximately 2% of each), but his total regeneration time stays constant at 3 hours. This significantly increases the Barbarian King's regeneration rate at levels beyond 30, ultimately reaching 1,900 per hour at level 40.
The Barbarian King will wander in circles around his Altar, occasionally seen jumping over walls as well.
The golden metal gauntlet on the Barbarian King's right hand is not seen when he is first summoned onto your village. Instead, it is the same grey color as the color of his shoulderguard.
His appearance changes as he levels up. At level 10 his gauntlet changes from grey to gold. At level 20 his shoulderguard gets a golden ring and spike.
The Barbarian King is basically the counterpart of the Archer Queen, and vice versa.
Even though the Barbarian King should sleep after battle, but he starts his regeneration countdown the second he gets wounded in battle, but doesn't recover health until the battle ends.
Starting at level 5, the Barbarian King obtains an ability called Iron Fist. This summons up to ten Barbarians and gives the Barbarian King increased damage and speed. This doesnot stack with the Rage Spell.
When The Iron fist is activated The Barbarian King Gains A Temporary Mini Rage Spell around him.