The Intratec TEC-9, TEC-DC9, KG-99, and AB-10 are a line of blowback-operated semi-automatic pistols. They were developed by Intratec, an American subsidiary of the Swedish firearms manufacturer Interdynamic AB. Introduced in 1984, the TEC-9 was made of inexpensive molded polymers and a mixture of stamped and milled steel parts. The simple design of the gun made it easy to repair and modify. It was a commercial success, with over 250,000 being sold.

A semi-automatic firearm, also called a self-loading or autoloading firearm, is a repeating firearm whose action mechanism automatically loads a following round of cartridge into the chamber and prepares it for subsequent firing, but requires the shooter to manually actuate the trigger in order to discharge each shot. Typically, this involves the weapon's action utilizing the excess energy released during the preceding shot to unlock and move the bolt, extracting and ejecting the spent cartridge case from the chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber, all without input from the user. To fire again, however, the user must actively release the trigger, allow it to "reset", before pulling the trigger again to fire off the next round. As a result, each trigger pull only discharges a single round from a semi-automatic weapon, as opposed to a fully automatic weapon, which will shoot continuously as long as the ammunition is replete and the trigger is kept depressed.