Planet Echelon

A Planet Echelon is a rating that determines how viable a planet would be in supporting alien life forms. All terrestrial worlds fall into one of the levels; the lower the level, the less viable the planet will be in allowing colonization. As a civilization gradually expands across an entire planet, the echelon may decrease due to environmental damage. Although the rating can decrease, it cannot increase unless advanced terra-forming technology is utilized.

Echelon 9
The planet is practically untouched by any civilization, as resources are extremely abundant and the atmosphere is composed of mostly nitrogen. Very few echelon 9 planets have ever been encountered, and the few that have exist in mythology as being reminiscent of the Garden of Eden. Climates are generally mild, with few extreme temperatures. It is rumored that the Dark Oculus was an echelon 9 planet over a dozen millenia ago. No other inhabitants besides the homogeneous populations of the indigenous races.

Echelon 8
Although not as rare as echelon 9 planets, echelon 8 planets are still very elusive. The planet is still practically untouched by any civilization, but a rogue comet or large-scale natural disaster may have done some damage to the environment. Resources are still plentiful. Climates are generally mild, with few extreme temperatures. The environment is completely untainted by pollution or any other bi-products of industry and civilization. The planet has no other inhabitants besides the homogeneous populations of the indigenous races.

Echelon 7
Although not as rare as echelon 8 planets, echelon 7 planets are still fairly hard to find. The planet may have been exposed to a planetary surveillance drone launched by a civilization. The planet may have been victim to a meteor shower or a slight shift of the axis, bearing limited, but permanent, damage to the environment. The planet has extremely few other inhabitants besides the homogeneous populations of the indigenous races. Although tiny settlements may have been established on the planet's surface, it has no permanent extra-terrestrial inhabitants. As soon as an extra-terrestrial settlement on an echelon 7 planet grows larger than a population of 40, the planet is considered to have descended to echelon 6.

Echelon 6
A more common score, planets usually have a rating of echelon 6 by the time space-faring civilizations attempt to colonize it, and also when the sentient inhabitants of the planet start to evolve and work together. As time passed, geographic changes may have affected how the planet's conditions work. Some natural resources may be gone, and natural disasters may have caused permanent damage to the surface. The environment is mostly untouched by pollution and other bi-products of industry due to the infant state of the extra-terrestrial colonies.

Echelon 5
Being the most common rating, echelon 5 is the rating of a planet that has a reasonable civilized presence on it. There is still a plethora of untouched resources. At this level, a civilization may realize that the resource the planet provides are finite, and establish their own ways of producing resources, such as capital and labor. Echelon 5 planets are also prone to extreme temperatures that significantly deviate from the planets of the predecessor ratings.

Echelon 4
At echelon 4, the planet may be hazardous to live on. The resource consumption has surpassed the production, and the atmosphere is damaged by pollution or through other means. Planets that suffer from frequent natural disasters or experience a change in axis tilt will quickly descend to echelon 4. Echelon 4 planets are prone to extreme temperatures that significantly deviate from the planets of the predecessor ratings; temperatures extreme enough that it could be fatal to sentient beings. A well known echelon 4 planet is the ice world of Yoth.

Echelon 3
Resources are not as numerous on echelon 3 planets. Damage to the environment may allow for overexposure to UV light, a decrease in the quality of the air, or unclean water. Planets with extreme environments or mono-climatic settings (e.g. ocean world, desert world), such as Aquamarine, which are only suitable for a specific type of sentient being, quickly descend to the echelon 3 rating.

Echelon 2
Resources are rare, the environment is hostile, and only a few civilizations are capable of settling this world, although the benefit of settling such a world in this condition are questionable.

Echelon 1
Echelon 1 planets, reminiscent of a living hell, always have very extreme temperatures that are fatal unless special equipment is utilized. Few sentient beings reside on echelon 1 planets, and they have spent hundreds of thousands of years adapting to the planet. Abundant, severe, and prolonged natural disasters, environmental damage, and horrendous air quality are also key features that give a planet a rating of 1. This rating includes any planets that are in the extremely close proximity of a star, adjacent to black holes, or are mere husks due to all of its resources being consumed.