Technological Achievement Tiers

The Forerunners categorized the Technological Advancement of civilizations into Tiers. This system was later adopted by the Covenant, and subsequesntly, the Intergalactic Republic. All life and civilizations in the universe fall into one of the categories. The lower the Tier number, the more advanced the civilization's technology is/was.

Tier 7: Pre-Industrial
Tier 7 is one of the most common and stable states, with limited weaponry and environmental threats. Societies tend to be small and scattered, driven by subsistence farming, foraging, or hunter-gathering needs. Technology is limited to simple hand made tools, weapons, or agrarian implements and methods, but a very broad understanding of planetary and solar mechanics is not uncommon. All species are part of this of this Tier until they reach a cultural and industrial renaissance.

Tier 6: Industrial Age
Tier 6 is often the pinnacle for a civilization. Agrarian societies can remain stable in the pre-industrial stage, but Tier 6 population strain and mechanized food production invariably create political and economic pressures very few can balance. Moving past this usually promises advancement. Some societies improve environmental and medical understanding concurrently with mechanical and transport advancement. Those that do not are frequently doomed.

This level is also where the Unggoy were before joining the Covenant. It is possible that the Jiralhanae stood in this level before joining the Covenant, because they had recently rediscovered the radio and flight before they were found by the Covenant.

Pre-UNSC humanity entered this age near the end of the 18th century, with the advent of steam technology.

Tier 5: Atomic Age
Tier 5 species usually begin focusing on clean energy production. The occasional belligerent species will use atomic energy for weapons, often resulting in mass extinctions. In-atmosphere craft are a hallmark, often leading to manned space flight, albeit in a short-scale.

Pre-UNSC humanity entered this age in 1945, when the atomic bombs were first dropped.

Tier 4: Space Age
Tier 4 is often the final resting place for species intelligent enough to break free from their cradle's surface only to fill the gulf surrounding it with war. Their comfort-focused technology can include medical advances.

Pre-UNSC humanity as well as the Earth Alliance reached this level in 1957, when the first satellite was launched.

This level is also where the Kig-yar and Yanme'e were before joining the Covenant.

In some period of their history the Jiralhanae reached this level, but because of a bloody civil war between rival master-packs, their civilization fell back to the pre-industrial age.

Tier 3: Space Faring
Species has efficient Slipspace, Hyperspace, and Quantum Gate navigation, mass drivers, and semi-sentient AI (though their creation requires memory transfer from the freshly deceased and/or cloning). They have had no outside influence. Usually, this Tier has also created prototypes of blaster, laser, and ion weaponry, if they have not already.

The UNSC stood at this level before the Human-Covenant War. This level is also where the Lekgolo were before joining the Covenant.

Tier 2: Intersteller
The species has the ability to perform exceedingly accurate Slipspace and Hyperspace navigation, and man-portable application of energy manipulation. The unified state of the 26th Century Covenant stood at this level.

Both San 'Shyuum and Sangheili brought the other races of the Covenant to such a high technological level when incorporating them into the Covenant. The two primary extant interstellar civilizations were space-faring prior to discovering Forerunner artifacts - or each other - but they have not successfully reverse-engineered those artifacts.

The UNSC entered an earlier level of this tier at some point during the Human-Covenant war. By the end of the war, with warships such as the UNSC Infinity, humanity stands at this tier of knowledge and near-full understanding from the studying of reverse engineered Forerunner and Covenant technologies, continued research in the field, as well as research in the laboratory. Though, due to the remnants and threat of the Covenant military, equipment so far is not as widely mass produced yet with the exception of the Infinity and very few others.

All Intergalactic Republic races, with the exception of the Earth Alliance, represented by the UNSC, are part of this Tier. The amount of time they have spent in this Tier, however, varies. While the UNSC have been in this Tier for less than a century, factions like the Galactic Republic and Protoss Empire have been in this Tier for thousands of years.

Tier 1: World Builders
The species has the ability to manipulate gravitational forces, create fully sentient AI, fabricate super-dense materials, perform super-accurate Slipspace navigation, the ability to create life, and the ability to create worlds (e.g.; Onyx, the Halo Array and The Ark).

The Forerunners along with Prehistoric humanity and Prehistoric San 'Shyuum are the only known civilizations to reach this level. However, the Intergalactic Republic is considered part of this Tier, as they have many of the Tier 1 requirements, and even some Tier 0 requiements.

Tier 0: Transsentient
As the Forerunners had no examples of civilizations with technological accomplishments greater than themselves - with the exception of the Precursors - this is a theoretical ceiling. However, the Xel'Naga, the 'creators' of both the Zerg and Protoss species, are believed to have been part of this Tier. It is suspected that they can travel across galaxies and accelerate the evolution of intelligent life.

The Intergalactic Republic can, to some extent, accelerate the evolution of life, and have the ability to travel between some galaxies, such as the companion galaxies and the Milky Way Galaxy.