A railgun is a linear motor device, typically designed as a weapon, that uses electromagnetic force to launch high velocity projectiles. The projectile normally does not contain explosives, instead relying on the projectile's high speed, mass, and kinetic energy to inflict damage. The railgun uses a pair of parallel conductors (rails), along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail. It is based on principles similar to those of the homopolar motor.As of 2020, railguns have been researched as weapons utilising electromagnetic forces to impart a very high kinetic energy to a projectile (e.g. APFSDS) rather than using conventional propellants. While explosive-powered military guns cannot readily achieve a muzzle velocity of more than ≈2 km/s, railguns can readily exceed 3 km/s. For a similar projectile, the range of railguns may exceed that of conventional guns. The destructive force of a projectile depends on its kinetic energy and mass at the point of impact and due to the potentially high velocity of a railgun-launched projectile, their destructive force may be much greater than conventionally launched projectiles of the same size. The absence of explosive propellants or warheads to store and handle, as well as the low cost of projectiles compared to conventional weaponry, come as additional advantages.Notwithstanding the above advantages, railguns are still very much at the research stage after decades of R&D, and it remains to be seen whether or not they will ever be deployed as practical military weapons. Any trade-off analysis between electromagnetic (EM) propulsion systems and chemical propellants for weapons applications must also factor in its durability, availability and economics, as well as the novelty, bulkiness, high energy demand and complexity of the pulsed power supplies that are needed for electromagnetic launcher systems.