Guardians of the Stars
The simplest way to kill or injure at a distance is still with a projectile. Conventional weapons use the expanding gases from a burning chemical propellant to push a projectile down a barrel. Modern conventional weapons use light polymer-cased or caseless telescoped ammunition, in which a projectile is embedded into a block of solid propellant. This reduces the ammunition weight and bulk so that more shots can be carried.
An Electrothermal-Chemical (ETC) weapon uses a plasma cartridge to ignite and control the ammunition’s propellant, using electrical energy to trigger the process. ETC increases the performance of conventional solid propellants, reduces the effect of temperature on propellant expansion and allows for more advanced, higher density propellants to be used. This requires not just ammo, but energy to create the plasma.
Liquid Propellants are an advanced option for conventional chemical propellant weapons. Propellant and oxidizer are kept in a separate bottle, then squirted into the firing chamber and ignited electrically when the trigger is pulled. Binary propellants are often used; the chemicals are inert until combined in the firing chamber. Liquid propellant is a bit more powerful and easier to store, but its chief advantage is precise control of propellant velocities. As power can be adjusted weapons can increase or lower power as needed at the cost or benefit of propellant. Pure LP weapons use caseless ammo and use bottles of both oxidizer and propellant.
Some systems combine ETC and Liquid Propellant together into ETCLP weapons. Combining the two gains the advantages of both, controlling the amount of propellant for each round and then providing exact and precise plasma burn of the fuel to maximize output. Though this requires an energy cell for power, propellant bottle, oxidizer bottle, and caseless ammo.