Railguns are simply scaled-up versions of personal Mag Rifles. They accelerate large metallic slugs along the weapon’s barrel, creating a steady spray of hyper-velocity rounds. Ammunition sufficient for one round of firing costs 50 credits.
Some weapons are simply too big to be comfortably used without a tripod, fixed support, or vehicle mounting. Others require specialized training in the use of heavy munitions.
Energy weapons use Type B power cells.
Some heavy guns can be fired to suppress. Double the usual ammunition is fired in one round, and every target in front of the weapon that is not under hard cover is automatically hit for half normal damage. A successful Evasion saving throw eliminates this damage.