Dual wielding is using two weapons, one in each hand, during combat. It is not a common combat practice. Although historical records of dual wielding in war are limited, there are numerous weapon-based martial arts that involve the use of a pair of weapons. The use of a companion weapon is sometimes employed in European martial arts and fencing, such as a parrying dagger. Miyamoto Musashi, a Japanese swordsman and ronin, was said to have conceived of the idea of a particular style of swordsmanship involving the use of two swords.
In terms of firearms and handguns, this style has been popularized by television, but is generally denounced by firearm enthusiasts due to its impracticality. Though using two hand guns at a time confers an advantage by allowing more ready ammunition, it is rarely done due to other aspects of weapons handling. Dual wielding is present in many films and video games, which have the freedom of ignoring the impracticality of the style. The term itself is often invoked in the context of games.
Dual wielding has not been used or mentioned much in military history, though it appears in weapon based martial arts and fencing practices. This style of combat requires special training, since an untrained user is unable to swing both weapons at the same time. To perform an attack by the defensive weapon after the first, the user needs to perform a separate and distinct action. The main advantage of using two weapons is the user can use one as a holding weapon after contact is made and use the other to attack the open area of the opponent. Otherwise, there is not much advantage compared to a user who wields a single weapon with both hands in terms of power and control. The latter has more maneuverability due to a more controlled center of gravity; a person using a single weapon can use their legs for kicking or tripping. A single-handed grip on each weapon also means it can be knocked away with a sufficiently powerful blow.