Civilization Tiers

General

The observers of the Angels categorize civilizations in the Multiverse into different tiers. Depending on the tier, the angels will either protect the civilization from the influence of others or may even act against the civilization if they see a threat in them. The exact categorization is decided by the guardian angels of a civilization. Each planet gets at least one angel assigned as its guardian angel. There are general guidelines for the tiers and when the right time is to let them step up to a higher tier, but these are not laws that must be followed by the guardian angel. If there is a good reason and they can argue it successfully against their boss, then they may categorize a civilization differently than the standard guidelines would suggest. This system was introduced as each civilization is different.

Tiers

Tier 1 - Primitives

Primitive Civilizations have formed smaller tribes or even nations, but have neither control over their whole planet nor advanced technology. Their society depends heavily on manpower for all kinds of productions and daily work. Primitive machines may exist and help the species to extend their strength, but they still depend on the direct manpower or control of others.
Tier 1 civilizations are under straight protection by the angels. It is forbidden for civilizations, that is not having the same home planet, to interfere with such civilizations. The civilization also is not allowed to receive help for their development. Their population count is generally low and most of their planet is most often natural and without signs of civilization.
There may be several tier 1 civilizations on the same planet.

Tier 2 - Industrialized

Most observed civilizations somewhen reach tier 2 status. This either happens by the development of industrialized machines or by the unification of the whole planet under a single nation or rulership. Manpower plays a far lesser role in the production and is surpassed by the developed machines many times. Another way to reach tier 2 is when a species is able to modify its own bodies in advanced ways. Most planetoid species reach tier 2 by becoming able to modify their own DNA or these of their offspring. Tier 2 civilizations still stay under the protection of the angels and are not allowed to be conquered or suppressed by aliens. Yet, the angels allow contact with other civilizations by this point, yet still, restrict the transfer of high technology.

Tier 3 - Space Traveller

The time of expansion and exploration of space is the main focus of any tier 3 civilization. Simple rockets or a visit of the moon is not enough to be categorized in this tier. You either need the technology for interstellar travel, like a warp drive, or you need to colonize other objects in your solar system outside your own home planet. A moon base on the moon of the own home planet does not count. Another way to reach this tier is to spread to other solar systems. This need not happen by interstellar travel, but could also happen by using a portal or other holes in spacetime. Angels won't protect the civilization anymore from tier 3 upwards. Wars and conquests between tier 3 and tier 4 civilizations are allowed and not restricted by them. Angels are observers and peacekeepers, but not the babysitter of other civilizations.

Tier 4 - Space Empires

A space empire includes colonies in other solar systems or enough colonies around the own sun. The colonies must be self-sustaining and have a steady and permanent population.
The construction of a mega construction like a Dyson sphere, a ringworld or similar are also indicators to categorize a civilization as a tier 4 power. Typically, a tier 4 civilization has contact with other civilizations and is able to easily visit other solar systems. Their technology allows their population a comfortable life without the requirement for manpower anymore. Most work is generally done by machines or automatic processes.
Angels will observe tier 4 civilizations critically to ensure that they can't become a threat. This includes the usage of force and even the destruction of whole planets or the direct assassination of groups from that civilization to prevent the research of forbidden technologies or the construction of weapons with too much destruction potential.

Tier 5 - Threat

Technology can be a threat to others and their own existence. The Angels learned this lesson the hard way in the war in heaven. A civilization that reaches this level is able to control whole galaxies and has the resources and the technologies for inter-galaxy wars. The angels will restrict the expansion of such civilizations to give other lower civilizations a chance to develop. If the empire becomes a too big threat, then the angels may declare them contaminated and eliminate them or at least pushes them back to lower tiers of civilization.

Tier Z - Fallen Empire

Fallen empires are civilizations that are not developing anymore. They are neither colonizing new planets nor are they developing new technologies. They are mostly passive and are rarely interacting with lower civilizations. Some, like the angels, may decide to observe others and protect primitive civilizations against others or from self-destruction. Such a civilization had reached its peak and then collapsed at one point. Most often, civil war or the development of certain technologies prevents them from developing further anymore. Or the society has decided that they stop any further development. This may happen out of fear of self-destruction or after major disasters or religious reasons.