Goku powers up to Kaio-ken x3 as he charges at the opponent and roundhouse kicks them up into the air. Then, he flies up in the air and punches the opponent away. Next, he flies up over the opponent and down behind to double kick them further up into the air. Finally, Goku flies up into the air around the opponent and hook kicks them down into the ground, inflicting a huge amount of damage.
Goku uses this attack during his first battle against Vegeta. After being dominated by Vegeta's increased speed and power even with his Kaio-ken x2, Goku decides to use his Kaio-ken x3. Goku charges up and his power soon surpasses Vegeta's, much to the Saiyan prince's shock. Activating his Kaio-ken x3, Goku rushes at Vegeta and attacks him with the Kaio-ken Attack, knocking him many meters away into a mountain.
Appearances in games
Kaio-ken Attack was named in the Budokai Tenkaichi video game series, where it is one of Goku (Early)'s Blast 2 attacks. In Budokai Tenkaichi 1 and Budokai Tenkaichi 2, the name was given to Goku's other Kaio-ken rush attack, Kaio-ken Finish; this was later fixed in Dragon Ball Z: Budokai Tenkaichi 3 and Dragon Ball Z: Tenkaichi Tag Team. The Raging Blast games and Dragon Ball Z For Kinect feature the Kaio-ken Attack and Kaio-ken Finish as separate attacks. It is one of Goku's Special Attacks in Battle of Z.
In Dragon Ball Xenoverse 2, it appears under the name Kaioken Assault as one of Goku's Super Skills which the Future Warrior (Xenoverse 2) can obtain by purchasing it from the Skill Shop in Conton City.
- In Xenoverse 2, if a male Future Warrior has Male Voice Option 8 selected as their voice option, when performing this technique the Future Warrior will mispronounce the Kaio-ken as KAY-O-ken rather than the correct pronunciation, however it is actually mispronounced on purpose by the voice actor (Curtis Arnott/Takahata101, voice of TeamFourStar's Nappa from the Dragon Ball Z: Abridged online parody series who previously did official voice work for the english dub of Xenoverse) for humorous effect as a in-joke reference to its mispronunciation in various dubs.
- Like with the Kaioken Kamehameha and its x4 and x20 multipliers, the Kaioken Attack can be used even when the Saiyan Future Warrior is transformed in any Super Saiyan form, despite Goku stating in Dragon Ball Super that other than the Super Saiyan Blue Kaio-ken, using the Kaio-ken and Super Saiyan forms together would kill the user due to the form making the precise ki control necessary to use the Kaioken safely impossible making it fatal to the user (unless one is already dead as Goku was able to use it while deceased when he fought Pikkon in Dragon Ball Z). The Warrior's ability to do so is left unexplained though presumably it is either an oversight or the developers ignored it for gameplay reasons (similar to how the Future Warrior is able to use the Spirit Bomb and Super Saiyan Bomb even as a Super Saiyan 2 and Super Saiyan 3). It should however be noted that the Warrior cannot actually use the Super Saiyan and Kaioken Awoken Skills together as their is only a single slot for Awoken Skills and can only use the Kaioken and Super Saiyan forms together when using Kaioken-based Super Skills or Ultimate Skills and they can use the Kaioken with other Awoken Skills such as Turn Golden, Potential Unleashed, and Kaioken itself.