First off there is the "Big Gun". When I say big I mean BIG, as in so big it needs to be mounted on specially made railway tracks or on the side of a mountain. With a big gun you have a big shell which means big destruction. Not only that but the sound of a huge shell traveling through the air is more than enough to scare the crap out of anyone. The shells, while good at wreaking havoc themselves, can also be fitted to carry chemical, biological, and nuclear warheads. That makes the gun ten times more effective. The biggest setback to the idea of using a big gun is that it can't be hidden at all, meaning that a well placed bomb can dismantle the whole thing. It is also very expensive to build and operate as it would require a ton of materials for the gun and the shells. It is not very cost effective, although it is still a good terror weapon for the limited time it can be used.

Next comes the lasers. While it might sound like a good idea to have an orbital space platform capable of emitting a highly concentrated beam of light that can melt through anything planet side the reality of the idea is that it is as practical as a screen door on a submarine. First of all it takes a huge amount of energy to create a beam with enough power to travel a hundred miles to the surface and still pack enough punch to do serious damage. That means the laser would need to be huge. Anything that is huge and stationary makes for a great target, so one missile could easily put it out of commission. And with the huge costs involved in development and construction it would be more cost effective to develop killer potatoes than to build a giant laser.

On to the chemical weapons. This includes everything from mustard gas to nerve gas. Chemical weapons have proven themselves to be very effective at killing and maiming people, as well as cheap in comparison to other weapons of mass destruction. The only two major problems with a chemical weapon concern delivery and the ability to protect against it. With the aid of a special suit and gas mask it is rendered completely useless as a killing weapon. However, the majority of the world's population doesn't own any adequate chemical protection. As far as delivery goes you would most likely need a large plane or missile to transport the chemicals to their target. There is also the option of sabotaging chemical plants that are near to large cities. All in all chemical weapons are the ideal weapons for those madmen who want to kill thousands and save a ton of cash while doing it.

Then there's the biological weapons. Biological weapons contain large amounts of organisms that cause infections which usually result in death or disability. Basically they are the military's version of the flu. They are very expensive to develop because they are essentially living weapons, and you have to keep them alive for them to kill. Not only that but you don't just find huge quantities of highly dangerous pathogens in your backyard (if you did you more than likely wouldn't be reading this). But once you have found and successfully cultivated a colony of pathogens you can easily grow more at little cost. These weapons are very dangerous not only because they can kill large numbers of people but also because they can spread rapidly with the winds and human-to-human contact. Thus these weapons have the greatest potential of destructive power because once they are unleashed there is virtually no way to stop them from creating a widespread epidemic. As for delivery a simple airburst over a city with a missile or bomb dropped from a plan would be effective. There is also the more discrete method of having a person with a colony in a small container spread the disease in the target area. With all this in mind they are by far the most powerful doomsday weapon (as far as the number of bodies that'll be piled up) and well worth the costs to develop.

Finally there are the infamous nuclear weapons. The first major type of nuclear weapon is the dirty bomb, nicknamed the poor man's A-bomb. It consists of radioactive materials, usually uranium or plutonium, wrapped around a conventional bomb. When the bomb goes off there is no nuclear blast it simply spreads radiation all over the surrounding area. It is moderately effective but expensive because uranium and plutonium are hard to find.

If you were somehow able to get your hands on some uranium or plutonium why not make a better bomb? I'm talking about a fission bomb, a nuclear weapon that derives its destructive power from the splitting of atoms. There is also the thermonuclear bomb which is similar to the fission bomb except that it also deals with fusion (atoms being fused together) which creates more energy and thus more destruction. The nuclear blast from the bomb instantly vaporizes everything within a small radius. It also creates a shockwave which easily rips through cars, buildings, and most importantly people. You also have the radiation which can cover a 25 mile radius from the initial detonation. Winds can also carry nuclear debris from the ruins and reach as far away as a few hundred miles. These two nuclear weapons are expensive to build because of the huge costs in engineers, facilities, and nuclear material. They are also very time consuming endeavors. But seeing as how they are the mother of all destructive manmade weapons they are worth the costs.

Since I've given you a basic understanding of the various doomsday weapons I would like to explain the ethics of using them.

Now that I've finished explaining that you're ready to choose your doom...!