The Gauss rifle, also called a "coil gun," is a device used to propel a ferromagnetic projectile by accelerating it through a process of electromagnetic induction.
In essence, a hyper-magnetic bolt or particle is rapidly drawn through the barrel using metal coils. When pulsed with a current, the coils briefly produce strong electromagnetic fields to which the particle is heavily attracted. This causes the projectile to be propelled at speeds surpassing traditional chemically-propelled projectiles such as bullets.
The Gauss rifle (and Gauss gun) are named after German mathematician Carl Friedrich Gauss, who formulated mathematical descriptions of the magnetic effect demonstrated by magnetic accelerators.
The Gauss rifle is a coil gun featured in Fallout Shelter that fires shards of metal at high speeds using magnetic coils that are powered by microfusion cells. Dealing a minimum of 16 damage per attack, it has the highest damage output for a projectile-based rifle in the game.