A rubber band gun is a toy gun used to fire one or more rubber bands (or "elastic bands"). Rubber band guns are often used in live-action games such as Assassins, in which they are common and popular toy weapons. They are also common in offices and classrooms. Rubber band guns have been popular toys that date back to the invention of rubber bands, which were patented in England on March 17, 1845 by Stephen Perry. Rubber band gun types Clothespin Clothespin rubber band guns are the simplest form of RBGs, being very easy to produce. Its firing mechanism consists solely of a clothespin with a rubber band placed between its jaws. The gun may have more than one clothespin, thereby allowing multiple shots. Repeating Most rubber band guns are of repeating nature, giving the user more firepower than single shot designs. They range from step-up-action guns and single rotor semi autos, to removable magazine automatic weapons. To simulate real life repeaters, there have been designs that require users to operate a bolt, pump a pump, pull back a hammer, or rack a slide. These may be impractical against other automatic rubber band guns, but give the user the psychological response of real firearms. Most repeaters fall into one of two categories: Escapement Escapement rubber band guns are capable of firing at least three rubber bands when fully loaded. Escapement rubber band guns are available in semi-realistic shapes, including pistols, rifles, and shotguns. They form the basis of almost all automatic rubber band gun systems. They are usually made of wood (although many Lego-based designs have been produced), and most have a strong machined plastic firing mechanism, consisting of a rotor where bands are hooked, and an escapement mechanism that lets the rotor rotate one position, releasing a rubber band. In Lego designs, a gear is commonly used in place of a conventional rotor, and due to how fine the teeth on the gear are, the escapement allows a rotation of more than one tooth, requiring rubber bands to be loaded a set number of teeth apart. Automatic Fully automatic rubber band guns are similar to automatic firearms, in that the gun's mechanism is powered by the projectile (in the case of automatic rubber band guns, the potential energy stored in the stretched rubber band). Many mechanisms have been devised by various online designers such as: A modified releaser that