Casters, once called "spell guns," are magical weapons which fire shells that have the effects of spells. When the mana started to run out people started putting the spells in cartridges. Each of the 20 different types of cartridge has a diffrent effect. Caster shells are rare and expensive, and few wizards still know how to enchant them.
Caster (for
Tri-Stat)
Item of Power 1x3 = 3
Easy To Lose
Special Attack "#3 shell" 1x4+ 1 = 5 (60 damage attack)
Affects Incorporeal
Concealable
Hand-Held
Limited Shots 2x-20 = -40 (3 shots)
Unreliable
Alternate Attack "#12 shell" 1x1 = 1 (20 damage attack)
Incapacitating
Limited Shots 2x-20 = -40 (3 shots)
Unreliable
Notes:
I was generous with the number of shots. Usually a character will only have one or two shells of a given type. There are obviously many more types of cartridge available, but they are hard to get and characters should be required to undertake a minor quest to acquire the very rare and powerful ones, like a #4 or #13.
Another way to write this weapon up is to treat the caster as a Major Gadget (or two) and then write up each cartridge as a different Special Attack.