The Hadouken is an iconic attack in Street Fighter that appears to produce flames. But what exactly is it? I skimmed the Street Fighter Wiki, but it just says that it's "energy" that is "as warm as normal body temperature, contrary to popular belief that it is a fireball".
So what exactly is a Hadouken? Is it a magical spell? Some sort of ancient martial arts technique that heats up the air? Something else?
The designer of the first game, Takashi Nishiyama, talks about the specific move’s inspiration:
I was inspired by anime and manga from the time, so for example the Hadouken was inspired by a Japanese anime called Space Battleship Yamato. In that, the battleship has a laser missile called Hadouho — it collects energy and then blasts it into space, destroying the enemy. That that's where I got the idea for the Hadouken.
The name apparently is directly derived from the weapon in the show; 波動拳 ("wave motion fist") is the Hadouken and 波動エンジン ("wave motion engine" with "engine" in English) is the name of the weapon. A Wikia page on the weapon.
A picture of the Hadouho:
Wikipedia says this about the move:
The move is achieved by the character thrusting their palms forward, sending a surge of spirit energy (or ki1) towards the opponent ("chi1 blast").
On “chi”1, a supposed energy or life force in Chinese traditional medicine, Wikipedia says:
Qi1 is the central underlying principle in Chinese traditional medicine and in Chinese martial arts.
The practice of controlling one’s chi1 is called Neijing.
The in-universe explanation for this is using chi1, a concept in real-world Chinese martial arts.
1Note that all of these are the same thing; "ki" in Japanese is the same thing as "chi" or "qi" in Chinese
As both a martial artist and Street Fighter fan, the Chi explanation rings true. It also essentially functions as an extension of a fighter's will or spirit. In the 1995 Street Fighter cartoon, all moves like that, from Guile's to Bison's, were fueled by Chi, but could produce or be expressed different energy effects, from sound to heat [Chun Li's was an actual "fireball"] to yoga fire-----which was actual flame---- to electricity or electromagnetism to even flight.
Chi could also fuel physical moves, such as the Flash kick, Psycho Crusher, rolling attack, Spinning Bird Kick and Dragon Punch. There is no "magic" involved, thought there Are SF characters who use forms of magic or technology to power their attacks. Most rely on Chi in some form, though, as this form of energy is highly connected to a "Fighter's Spirit".
