A blow gun is a primitive weapon that has its origins in ancient history. The weapon is constructed out of a narrow, hollow lightweight tube. By blowing air into one end of the blow gun, a small dart or other projectile is fired from the weapon at several hundred feet per second. Although very simple, the blow gun has been used for centuries as an effective hunting weapon around the world.

The exact origin of the blow gun is lost in the annals of history. Many researchers believe that the weapon was invented in numerous locations across the world during the stone age. The earliest written references to blow guns have been dated to 2nd century Roman and Chinese sources.

The length of a blow gun usually varies depending on several factors. First and foremost, the longer the weapon, the more air flow is necessary to fire a dart effectively. If a hunter has powerful lungs and a long blow gun, it is possible to bury a dart several inches into a wooden target. Sport blow guns are often shorter than traditional hunting versions, since accuracy is more important than the force of the dart.

Blow guns are made from different materials depending on the location of manufacture. The modern blow gun is often made of a light-weight metal or durable polymer with a plastic mouth piece to transfer the full force of the user's air flow. Modern blow guns are usually segmented into several pieces to allow for easy cleaning. Ancient or home made blow guns are usually made out of bamboo or cane and can be made of a solid piece or segmented.

The most common projectile fired by a blow gun is the dart. Some hunters use a poison dart since the blow gun is not guaranteed to make a kill with one shot. The most infamous type of poison used is from the poison dart frog (of the Dendrobatidae family), which excretes a highly toxic chemical from its skin when agitated. Modern, professionally made darts are available in many different styles, such as broad head, the spear point, or "stunner" (very short dart consisting of a weighted rear end with a short point). Before darts were used, many blow guns fired pellets made from stone or clay.

In the United States, the blow gun is classified as a weapon, and is legal in all states except for California, Massachusetts, Texas, Florida, and Ohio. In American states where it is legal to own and use a blow gun, one must usually be at least 18 years old. It is illegal to own a blow gun in Canada, and any blow gun brought into the country must be deactivated by drilling a hole at the base of the weapon, or blocking the airway altogether.