Weapons Of Mass Destruction

Any weapon that causes near-total and indiscriminate destruction over a large area. What constitutes 'large' in this case is somewhat ambigous, however. These weapons are often devided into sub catagories like city-buster, planet-buster, star-buster, etc. based on the damage they are expected to cause.

The term is often abbreviated to WMD.

Known Types

Nuclear bombs

Nukes were historically the first weapon classed as a WMD, it works by compressing a mass of fissile material to a critical mass where natural radioactivity causes a runaway chain reaction causing a large explosion. The main differences between various nuclear weapons are in the fissile material used and the method to achieve critical mass.

KEWs

An acronym for kinetic energy weapon.

KEWs function by accelerating a large mass to a high velocity and smashing it into the target. The destruction is caused almost entirely by the released kinetic energy of the mass.

Industrial Mass Drivers can be used as these.

Antimatter Weapons

Antimatter holds a very large amount of energy that can be released very easily. The only thing keeping it's weaponisation from being trival are amat's high manufacturing costs and difficulty in keeping it contained until detonation of the weapon. Containment is commonly achieved using magnetic confinement or by surrounding each atom of antimatter with a protective buckyball. Both of these methods are mass-intensive and unreliable, however.

Other

Some biological weapons can be considered WMDs, although they seldomly cause the physical destruction WMDs are associated with, they may completely destabilise a biosphere, often with fatal results for anything depending on it.