Electromagnetic projectile weapons

Brief history:
* 1840s — early, but not workable, design of linear motor by Charles Wheatstone.
* 1905 —- Alfred Zehden designed a working linear motor (US patent 782312)
* 1912-03 — a patent for electromagnetic suspension by Emile Bachelet.
* 1934 — a monorail patent by Hermann Kemper.
* 1935 — a working miniature model of linear motor was constructed by Hermann Kemper.
* 1940s — a full-size model built by Eric Laithwaite.
* 1979 — first maglev (transrapid) train in public use, based on 1934 patent.
* 1980s — a tubular linear motor designed by Hugh-Peter Kelly.
* 1985 — first prototype railgun constructed in Yugoslavia.
* 2006 — prototype naval railgun test firing by US Navy.
* 2020-2025 — a proper capacitor for railguns expected to be ready.

Main problems for the weapons are lack of large/efficient enough capacitors, and overheating (which most notably causes massive rail degradation).

See also: Electromagnetic pulse (EMP) weapons

Mass drivers propel physical material, usually shaped shards of some metal, into unusually high speeds through the use of magnetic rails. These weapons gain most of their destructive power from the sheer speed (~3.5 km/s vs ~0.9 km/s) of the projectiles rather than from their mass like other conventional projectile weapons do.

They have various benefits over regular firearms that use an explosion to propel the slug: primarily the whole lack of explosion, no muzzle flash, completely soundless except what the trigger, reloading and the slug's massive speed cause. All in all, they make less noise than any silenced firearms. Unfortunately the technology is not particularly space efficient and is unlikely to become that to such extend that you'd see real handgun sized mass accelerators, but more likely in the SMG/rifle size with much larger barrel (though for different reasons than with firearms, so the weight shouldn't be affected that much).

Summary:
* No explosion
* No muzzle flash

Unfortunately most games prefer drama over realism, so you may see muzzle flash and even quite loud sound reminiscent of regular firearms regardless. Also, gauss guns have more significant benefits as replacements for turrets and other large cannons, especially those seen on warships.

Railguns are a variation that use literal rails, these have various flaws and benefits over other similar weapons, most notable is the need to swap the rails unfortunately frequently. These may also cause more sound as the slug "drags" across the rails.