Challenge: Alternate History: World War II/Pet Monster
The year is 1978. The American Initiative patrols the Panama Quarantine Line. From behind the Rocky Mountains, Remnant Columbia prepares to take back the rest of the continent and save the Holdout States. The Greater East Asian Co-Prosperity Sphere is showing its first signs of decay while the British are just beginning to pull themselves back together. It is 1978, and it has been thirty-seven years since the machines came.
The New War started in Europe. Nobody knows if they're a German experiment gone rampant or if the Nazis were just unlucky. The first machines were clunky and inefficient. Very simple, and relatively easy to destroy. They've been getting better. They adapt, changing form and function in response to experience and often demonstrating the ability to shift between different modes- machines of the artiglieria-variety are normally small, speedy things with little firepower but they can convert into a static form, rooted into the ground for support, which can blow holes through concrete walls.
As near as anyone can tell the machines are specifically designed to hunt and kill sapient life. They ignore most other organisms except when they need to refuel. Machines run on cold fusion generators that convert carbon most efficiently (and which are too bulky for machines to come in sizes smaller than a house cat, thankfully) but blood is even better for them, somehow. The smarter ones even seem to get a euphoric kick from it.
Drinking blood also triggers replication. The amount required to do this is equal to six quarts, which has led many scientists to believe that the machines were designed specifically to eliminate human life. Machines make near-perfect copies of themselves which gradually change over their generations, being subject to the normal processes of natural selection. Worse, though, is that the machines are able to change themselves, so that a single machine may over the years go from a swift, lightly-armed form designed for traversing rivers (possibly with an alternate mode for terrestrial travel) to a tank-like walking behemoth that has lost none of its speed.
As a rule, the more specialized a machine is the longer it takes to adapt to a new specialty (and the more reluctant that it appears to be about doing so, even when the need is great), and even the smallest changes (like a minor shift in the range of light that is processed by its "eyes") take days or weeks to finish. Modifying alternate modes takes years, and it isn't uncommon for a machine to have a mode akin to a vestigial limb, that no longer serves any purpose but is possibly kept around as a "just in case." Because alternate modes can restrict the development of the standard mode, their existence further restricts how easily a machine may adapt itself. This may be why about a third of the machine population has no alternate mode.
While no two machines are exactly alike, similar experiences and environmental pressures result in roughly similar forms and abilities in a case of convergent evolution. These similarities are classed together as "Varieties," as is illustrated with the aforementioned artiglieria. "Orders" are general developmental paths that have been mapped out in the machines. Over many years studies have allowed researchers called machinists to predict with some accuracy how a machine will adapt in response to a particular pressure.
An astonishing diversity exists in the machine population. They may swim, fly, burrow, move on treads or wheels, walk, slither, or drift on the wind. They can attack with blades, bullets, explosive powders or liquids, poisons, sonic vibrations, electricity, fire, or acid. Some have senses that we are well-familiar with, like sight and taste. Others are sensitive enough to heat to feel the presence of a human body from twenty feet away. And there are even some that can detect thoughts.
In order to avoid pointless capitalization of "machine," the word is used only for the nasty monster machines that kill people. When referring to anything else, the words "mechanism," "contraption," or "apparatus" are used.