"Oh... it's the Kaio-ken attack. It's like a massive upsurge of energy. Everything is heightened: power, speed, even hearing and vision improve dramatically. You sort of become a super-self. But it can only be sustained for a short time, so you have to get the job done quickly."
Kaio-ken (界王拳; lit. "Fist of the King of Worlds" or "World King Fist") is a fighting technique invented by King Kai; however, Goku is the only person ever able to use it successfully. It is a technique that multiplies the user's ki for a "heart beat", enabling them to inflict serious damage to opponents who are considerably stronger than them. While in the state, the user's aura color becomes crimson. The technique requires the use of Ki control to handle it properly.
As a result of the Kaio-ken, the user's base power level, strength, speed, and senses greatly increase for an instant (though training can allow for longer use shown during Goku's fight with Frieza). The only change produced by the basic Kaio-ken to be quantified in the series is that it doubles the user's power level. As the series progresses, Goku demonstrates the ability to heighten the effect of the Kaio-ken to increasingly higher multiplications. There is an inconsistency in that Kaio-ken and Kaio-ken x2 appear to have the same effect, despite Goku and King Kai apparently believing the latter to be a more powerful buffer. Despite this, Kaio-ken x3 and above all consistently multiply the user's power level by the respective multipliers.
When Goku first learned the Kaio-ken, the furthest he could handle was the Kaio-ken x4 (though his body was heavily damaged), but through training at 100x gravity and then later with his dramatic strength increase after his fight with Captain Ginyu, he was able to withstand astounding multiplications of the Kaio-ken technique, such as Kaio-ken x10 and Kaio-ken x20. The highest multiplication for the Kaio-ken ever seen was the Kaio-ken x100, which Goku used against Lord Slug. The technique, however, has its substantial flaws. If the user multiplies their base ki too much, the uprise of ki could easily obliterate them, or severely damage their body, as it did Goku's. After using the Kaio-ken x4 to overpower Vegeta's Galick Gun, Goku's entire body was thrashed, and he could barely move without hurting himself. Even one friendly slap on the back from a gracious Yajirobe caused Goku to scream out in agony. King Kai tried to master this technique himself but failed and taught Goku instead.
Uses of the Kaio-ken
Dragon Ball Z
The first time Goku used the Kaio-ken was during the Saiyan conflict when he used it to catch up with and cripple Nappa before he could kill Gohan and Krillin with his Break Cannon mouth blast. Later, while Goku started to battle Vegeta, he realized he could not defeat Vegeta even with the Kaio-ken; so he powered up to Kaio-ken x3, raising his battle strength to over 24,000 and overpowering Vegeta. To prevent Vegeta from destroying the Earth with his Galick Gun, he used a Kaio-ken x3 Kamehameha, a combination of the Kaio-ken x3 and the Kamehameha, in an attempt to save himself and the Earth, initiating a Beam Struggle. When both of their attacks proved unable to overtake the other, Goku used the Kaio-ken x4, surging through Vegeta's Galick Gun and blasting him into the sky.
Goku also used the Kaio-ken briefly when he fought Vegeta's Great Ape form, but was whipped aside by Vegeta's tail, surprised at Vegeta for remaining as agile as ever even in the huge size of the Great Ape transformation. During the Battle on Planet Namek, Goku uses the ability during his fight with Jeice and Burter in order to increase his power up to 300,000 according to Dragon Ball Z: The Anime Adventure Game, so that he could outmatch Burter and Jeice's combined power level of 175,000. Later when Goku fought Captain Ginyu, he demonstrated his Kaio-ken in a prolonged way, increasing his battle strength to a power level around 180,000, thus shocking Ginyu and Jeice. After being healed in the rejuvenation chamber following his attack from Vegeta when Goku himself had switched bodies with Ginyu, Goku battled with Frieza using a Kaio-ken once again.
After realizing Goku was stronger than the others he had battled from Ginyu to Piccolo and even Vegeta, Frieza used 50% of his maximum power, which gave him an enormous power boost. According to Tien Shinhan and King Kai in the manga, Goku was using Kaio-ken x10 throughout the fight, to have even a chance at battling Frieza, but even this was not nearly enough. Goku then attempted to use the Kaio-ken x20, which very briefly gave him speed and power enough to strike Frieza, setting him up for a Kamehameha, which Frieza amazingly held off with one hand before taking the full extent of the blast. Unfortunately, though showing physical signs of being harmed, Frieza was barely hurt by the attack. He did however appear shocked by Goku's power, remarking that there was "something strange" about him and wondering how a Saiyan could have such "incredible power". The attack left Frieza feeling somewhat threatened, as he remarks to himself that he "must take him out now!" A short time later, Goku transformed into a Super Saiyan, which greatly overshadowed the Kaio-ken.
Goku's battle against Frieza is the last time the Kaio-ken is used in the manga, as the introduction of Super Saiyan outclassed it. However, in the anime filler fight against Pikkon at the Other World Tournament, Goku uses a Kaio-ken and Super Saiyan combination (something he calls a "Super Kaio-ken"), which gives him an incredible power increase. Because of this one instance, it appears that Goku can also demonstrate the Kaio-ken's usability in transformed states, which potentially means he can make his transformed forms many times stronger. However, Goku also is very exhausted after using it due to the stress of the Super Saiyan form combined with this technique and cannot perform this technique unless dead. If used alive, he would otherwise be killed using the Super Kaio-ken.
Dragon Ball Z movies
Goku uses the Kaio-ken technique to battle the villains in Dragon Ball Z movies 2-6.
In Dragon Ball Z: The World's Strongest, he first uses it to deflate the bio-warrior Misokatsun. He uses it again soon after to free himself after being frozen solid by Ebifurya, and then easily takes out both Ebifurya and Kishime with it. He later uses the Kaio-ken x3 to attack Dr. Wheelo's giant robotic body and succeeds in breaking off Wheelo's right arm. The two then engage in a Beam Struggle similar to the one Goku and Vegeta have in the Saiyan Saga, and, just like in that struggle, Goku overpowers Wheelo's blast by using the Kaio-ken x4.
In Dragon Ball Z: The Tree of Might, Goku first uses the Kaio-ken to avoid getting hit by the Great Ape Gohan, but is eventually knocked down by him. Goku later uses the Kaio-ken again to defeat all of Turles' henchmen. After Turles becomes more powerful with the fruit from the Tree of Might, Goku uses the Kaio-ken x10 (Kaio-ken x20 in the Funimation dub) to attack him, but is still unable to keep up.
In Dragon Ball Z: Cooler's Revenge, after Cooler transforms and becomes far more powerful, Goku uses the Kaio-ken to attack him, but has no success. Cooler even flies through Goku's Kaio-ken Kamehameha combo.
Dragon Ball Super
According to Goku, using Kaio-ken alongside the Super Saiyan forms would be too overwhelming on the body, due to the forms using a lot of stamina, and would most likely result in immediate death. However, when Goku obtained the Super Saiyan Blue form, which required perfect innate ki control and a calm mind, utilizing the Kaio-ken technique alongside it became possible. So during his training, Goku began developing a new Kaio-ken technique for eventual use against Beerus. He first attempted the technique against Hit during the Universe 6 and 7 Gods of Destruction Selection Martial Arts Competition, noting that it was incomplete with only a 10% chance of success, meaning Goku needed absolute concentration when activating it, otherwise it would kill him. Goku succeeded in combining the transformation with the Kaio-ken x10, which gave him the ability to effectively counter Hit's improved Time-Skip technique. However, due to the Kaio-ken's risks, Goku could not keep fighting for very long, and ended up surrendering the match as his time had run out. After ending the technique, Goku was in extreme pain as he was suffering from extreme muscle contractions. Due to the reckless use of his Ki this way, Goku ended up suffering from Delayed Onset Ki Disorder for some time.
During the Zero Mortals Plan, Goku used the Kaio-ken once again in Super Saiyan Blue form while fighting Fusion Zamasu. He did this as a last resort to break Zamasu's halo after losing strength in both of his arms and having his left leg crushed. Though he succeeded in knocking Zamasu down with a swift kick from his right leg thanks to the Kaio-ken, Goku was immediately drained of his power afterwards and required a Senzu Bean.
Appearances in games
Goku has used the Kaio-ken technique in many of the Dragon Ball video games, usually as a power-up to increase his abilities or physical strength. He uses it in the Gokuden RPG series, Dragon Ball Z Arcade, Dragon Ball Z: Super Butōden, the Budokai Tenkaichi fighting game series, Super Dragon Ball Z, and Dragon Ball Z: Burst Limit. In the Budokai fighting game series, as well as Dragon Ball Heroes, the Kaio-ken is counted as a transformation rather than a technique; in Dragon Ball Z: Budokai and Dragon Ball Z: Budokai 2, this attack is dubbed as "King Kai Fist", which is more-or-less an accurate translation.
In Dragon Ball Z: Supersonic Warriors, in Krillin's "What-If" story, after dying of the heart virus, Goku (with Fortuneteller Baba's help) returns to teach the Kaio-Ken and Spirit Bomb techniques to Krillin so he can protect the Earth in Goku's place. Krillin can use these techniques in his level 3 form. Both Goku and Krillin will have their Kaio-ken activated if they are in a team-battle as the last team member standing, and when activated it will drain their HP slowly.
Kaio-ken appears in the Dragon Ball Z Collectible Card Game, on the card "Red Kaio-Ken Drill".
In Dragon Ball: Xenoverse, Kaio-ken appears as a transformation Super Skill usable by Goku (in his 1st and 4th Skillsets), Krillin (in his 5th Skillset), and Yamcha (in his 2nd Skillset). Goku can also use the X3 Kaio-ken (in his 5th Skillset) and X20 Kaio-ken (in his 6th Skillset)
"The higher your Ki when you transform, the greater the power-up! But it'll also become a great burden, so watch out!"
— Xenoverse 2 Kaio-ken Skill description
In Dragon Ball Xenoverse 2, all Kaio-ken skills have been united into a single Awoken Skill, giving higher levels of Kaio-ken based on how may filled ki bars the user has (1 to 2 bars for the standard Kaio-ken, 3 to 4 bars for 4x Kai-ken, and 5 or more for 20x Kai-ken). While in the Kaioken state, the user can revert to their base form by pressing the skill's assigned buttons to deactivate it. When in use the Kaio-ken drains stamina and will put the user into a guard break state if they run out of stamina while using it. Like in Xenoverse, it can be used by the Future Warrior regardless of race.
Unlike the previous game, Krillin and Yamcha can't use Kaio-ken, only Goku and the Future Warrior (Xenoverse 2) can use it. It can be obtained by the Future Warrior as a reward in Parallel Quest 08: "Invade Earth".
Additionally the Future Warrior and Goku can use the Kaioken Assault and Kaio-ken Kamehameha as separate Super Skills, along with the 4x and x20 version of Kaio-ken Kamehameha as separate Ultimate Skills. These skills can be use in conjunction with the Awoken Skill or without. They can even be used while in various Super Saiyan forms by the Future Warrior. After the Version 1.05.00 Update, SSGSS Goku can use the Super Saiyan Blue Kaio-ken as his Awoken Skill transformation in his Whis Symbol Gi 2 Skillset. While using his Super Saiyan Blue Kaio-ken state, Goku gains access to his X10 Super Saiyan Blue Kaio-ken form. Unlike the standard Kaioken, the Super Saiyan Blue Kaioken and X10 variant drain the user's Health instead of Stamina, and the health drain increases with the X10 multiplier. Due to the health drain, it makes both transformations more risky than the standard Kaioken and its multipliers (x3 and x20).
In the games Jump Super Stars and its sequel Jump Ultimate Stars, the Kaio-ken is used as Goku's Special B/Up Special via his 5 Battle Koma version, where it only is used for that one brief attack, which varies between the games. In the first game, Goku is by default in his Super Saiyan form, making it identical to his Super Kaio-ken attack, and it works as a charge attack in order to reach the full sequence of blows when fully charged. In the sequel, Goku instead is still in normal form in BK5, while his Kaio-ken sequence now involves rapid button taps in order to get the full sequence.
Dragon Ball Online
In the computer game Dragon Ball Online, which is set in Age 1000, it is said that between the end of the original manga and the start of the game, King Kai taught the Kaio-ken skill to the inhabitants of Earth. This includes Humans who since the end of the manga have began practicing different forms of martial arts, and the Namekians who fled to Earth after their planet was destroyed by Mira. The Majin race, who were not taught the technique, managed to learn it through mimicry. As such, the technique is obtainable by all three of the game's playable races.
The skill is learned by every class at level 35. The appearance and effects in the game are similar to how it appears in the anime: activating it engulfs the player in a flaring red aura. The self buff increases the players' movement speed, allowing them to run faster while traveling the environment, as well as their attack speed, chance of critical strike, and maximum attack power while in combat. During its use, both the player's LP (life) and EP (power) are drained and the skill cannot be deactivated manually, but instead deactivates itself when HP is considerably low. Kaio-ken also has a six-minute cooldown period.
The Kaio-ken technique can be amplified over x20, as never seen in previous uses by Goku in the original series. The only increase that comes with multiplying the Kaio-ken buff is the chance of critical strike; for example, activating it doubles the player's critical strike, and the following multiplication would put the increase at x3. Owing to it being accessible to all races and classes, it can be used to increase the strength of trademark techniques other than the Kamehameha, such as Special Beam Cannon, Wolf Fang Fist, Destructo Disc, and Big Bang Attack.
- The name of the technique has usually been pronounced incorrectly in the English dubs of the anime and video games ("KAY-o-ken", rather than "KAI-o-ken") despite being named after the correctly pronounced King Kai. However, Peter Kelamis (Goku's second voice actor in the Ocean dub of Dragon Ball Z) pronounces it properly in the Ocean dub of The World's Strongest and The Tree of Might, and Sean Schemmel (Goku's adult voice actor in the Funimation dub of the whole franchise) pronounces it correctly in Dragon Ball Z: Burst Limit and in most subsequent games that have been released. The Kaio-ken is also pronounced correctly in the English dub of Dragon Ball Z Kai.
- The only time Goku shouts "Kaio-ken times two" was briefly during the battle with Vegeta, in order to dodge an incoming energy blast. As previously mentioned, there appears to be no actual difference between the Kaio-ken and 2x Kaio-ken. According to the Daizenshuu, Goku's base power level at the time was 8,000 and Vegeta's was 18,000; Goku then powered up to 16,000 with the 2x Kaio-ken, and then 24,000 with the 3x Kaio-ken. If there was a difference between the Kaio-ken and 2x Kaio-ken, then Goku should not have needed to use the 3x Kaio-ken in order to overpower Vegeta.
- In an episode of the original Saban dub, Goku shouts "Kaio-ken times ten" and then "Kaio-ken times twenty" as he fires two Kamehameha blasts toward a comet that his spaceship almost collides with.
- The website for Dragon Ball Z: Battle of Gods states that "King Kai teaches Goku the "Kaio-ken" and how to gather energy from the planet into one great fighting energy ball. Later King Kai takes on the training of Yamcha, Tien, Chiaotzu, and Piccolo using the same techniques that were successful with Goku." It is unknown whether this statement refers to teaching the Z Fighters the Kaio-ken and Spirit Bomb techniques, or if it is referring to King Kai's training techniques.
- In Dragon Ball: Xenoverse, if the Future Warrior uses the 3x Kaio-ken with Male Voice Option 8 (which is actually the voice of Curtis Arnott/Takahata101, voice of TeamFourStar's Nappa from Dragon Ball Z: Abridged) he refers to it as Kaio-ken 3.0.
- In Dragon Ball Xenoverse 2, if Male Voice Option 8 (again Chris Arnott/Takahata101 from Dragon Ball Z: Abridged) is selected for the Future Warrior, then they will shout "KAY-o-ken" when performing the Kaioken Assault Super Skill, though its mispronunciation is done on purpose as an in-joke reference to the common mispronunciation of Kaio-ken in various dubs.
- Kaio-ken Attack
- Kaio-ken Finish
- Kaio-ken Kamehameha
- Super Kaio-ken
- Super Saiyan Blue Kaio-ken
- Maximum Kaio-ken
- ↑ Dragon Ball Z: Supersonic Warriors, 2004
- ↑ 2.0 2.1 2.2 2.3 Dragon Ball Xenoverse, 2015
- ↑ Dragon Ball Xenoverse 2, 2016
- ↑ Goku Black lines
- ↑ Dragon Ball chapter 229, "The Decisive Battle at Last!" (Page 01, Panel 01)
- ↑ Daizenshuu 7, 1996
- ↑ Weekly Shōnen Jump #12, 1991
- ↑ 9.0 9.1 3DS「ドラゴンボールフュージョンズ」第1弾PV on YouTube
- ↑ Dragon Ball: Xenoverse, Future Warrior: Male Voice Option 8