Kaiō-ken Attack (界王拳アタック, Kaiō-ken Atakku, literally: King of the World's' fist Attack) is Goku's side special move variant while in Kaiō-ken in Super Smash Flash 2. When executing the attack, Goku makes a brief stop and then dashes forward surrounded with a red burst of energy, dealing 8% of damage and moderate knockback to any opponent on his path. The attack may be more useful use a recovering move, as it covers a huge horizontal trajectory and does not render Goku helpless (unlike other recovering moves), making him able to use it over and over.
In the Dragon Ball universe, this move is very different. Goku powers up to Kaiō-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.
- In demo v0.7, Kaiō-ken Attack was closer to the actual attack in the Dragon Ball series, possessing a combo of punches and kicks, which was removed due to the excessive length of the special. It also covered a considerably larger distance, but rendered Goku helpless afterwards.
|Standard special move||Kamehameha|
|Side special move||Ki Blasts / Kaiō-ken Attack|
|Up special move||Instant Transmission|
|Down special move||Kaiō-ken|
|Final Smash||Super Saiyan Goku|