Three prominent Soviet engineers were asked to submit their own designs: Vasily Degtyaryov, Sergei Simonov and Alexei Sudayev.

[2] Although the RPD was ready for mass production during the final stages of World War II, it was adopted in 1948 and large scale delivery of the weapon did not begin until 1953.

[3] After the introduction of the Kalashnikov-pattern support weapons, such as the RPK and PK machine guns in the 1960s, the RPD was withdrawn from most first-tier units of the former Warsaw Pact.

[citation needed] The RPD is an automatic weapon using a gas-operated long-stroke piston system[8] and a locking system recycled from previous Degtyaryov small arms[citation needed], consisting of a pair of hinged flaps set in recesses on each side of the receiver.

[8] The movement of these flaps and the resulting locking and unlocking action is controlled by carefully angled surfaces on the bolt carrier assembly[citation needed].

The RPD has a manually operated lever-type safety mechanism that secures the weapon against accidental firing by blocking the bolt catch when engaged.

Unlike Degtyarov's earlier firearm patents, the RPD's return spring is located inside the butt.

[9] The combined belt segments are stored in a metal drum that is attached to a mount on the receiver, for a total of 100 rounds.

[citation needed] Standard accessories issued with the weapon include a sling, extra ammunition drums and belts (with either belt or shoulder pouches for same), oil bottle, cleaning rod (carried in a slot on the left side of the receiver),[10] (stowed in a compartment inside the stock), and drop case.

[citation needed] The cleaning kit consists of a rectangular metal clam-shell case that typically contains the following tools and spare parts: pin punch (used for disassembling the bolt), cleaning jag, multi-tool (includes screwdriver, small and large wrenches used for adjusting the front sight and gas system, respectively, and a notch for installing and removing the cleaning jag on the cleaning rod), broken case extractor, front sight adjustment tool, gas tube scraping tool, gas port reamer, spare extractor, spare extractor spring, spare firing pin.

[11] There are a number of spring steel "fingers" on the lid of the clam-shell case which press on the contents of the cleaning kit when closed to prevent rattling.

A further modified variant (sometimes referred to as the RPDM) includes an extended gas cylinder and a recoil buffer mechanism in the stock.

The RPD Carbine has a fluted 17.5-inch barrel, modern front sight, alloy handguard with rails, M249-type pistol grip and M4 recoil spring tube and buttstock.

[12][13] Because semi-auto RPD variants are manufactured using de-milled parts kits from full-auto RPD machine guns, in order to comply with ATF regulations the full-auto parts must be modified such that the resulting semi-auto rifle cannot be readily converted into a machine gun.

Additional portions of the bolt carrier that are necessary for full-auto firing, such as the sear engagement surface, must be machined off during the semi-auto conversion process.