As with many of Dan's attacks, it is a parody of another existing move used by all those who practice Gouken's style of martial arts (specifically the Hadoken). Though he mimics Gouken's one-handed motion, the technique lacks any comparable power. It also acts as a parody of the effect of Ko'ōken (虎煌拳? "Tiger Sparkle Fist") from the Art of Fighting series when the energy gauge is low (resulting in a projectile that flies at a poor range); an altered version of this also oddly acts as Ryo Sakazaki's main Ko'ōken in later King of Fighters games.
Executed in the same exact way as the Hadoken, the Gadoken is a projectile attack that Dan launches with one hand. Though the distance of the attack can be controlled depending on the punch button used, the attack's general range is extremely short, limiting its usefulness.
Despite the one-handed motion (which comically enough, may resemble a slap), if one looks closely, the ki projectile shows a single palm instead. In later games like how it was first done in the original Street Fighter Alpha, the Gadoken is done with a forward palm.
The attack does roughly as much damage as any other projectile in spite of its range, and can act as a rather limited method of defense against them. The attack can also be used as a limited combo extender and as way to hit a unexpecting opponent.