The Interstellar Community of Sovereign States classifies civilizations by technological reach, infrastructure and independence from a single planetary environment. Its six tiers describe capabilities. Separate societies of the same species can occupy different tiers, and political subordination does not automatically diminish a civilization's technical classification.
Also called the Cradle Stage, Tier 0 encompasses societies confined to a homeworld's biosphere and, at most, its immediate orbit. Chemical combustion, basic renewable power or early fission sustain their industry. They depend upon the planet's naturally stable climate and living systems and lack an independently sustainable offworld population.
A civilization's classification describes its present capabilities, irrespective of ancient offworld ancestry or concealed extraterrestrial activity.
The Asymptotic Stage encompasses permanent offworld settlements, asteroid exploitation, substantial orbital industry and routine interplanetary logistics. Fusion power and early antimatter applications may support a civilization's command of its home system.
Its practical transport remains below the FTL threshold. Even sending sublight craft into interstellar space does not, by itself, establish Tier 2.
Earth is a Tier 1 (System-Locked) civilization. It remains below the practical interstellar FTL threshold and retains Giza Convention protection under the ICSS.
A civilization reaches Tier 2 when it possesses a workable means of faster-than-light travel between star systems. A repeatably operable shipboard jump drive is sufficient before any vessel undertakes an interstellar journey or any colony is founded.
The Mahruni crossed this threshold through an indigenous jump drive while their entire territory remained within Seyrik. Their later protectorate relationship with Helios did not erase that capability.
Tier 2 marks entry into the ICSS's claimed jurisdiction. A qualifying sovereign state becomes subject to its interstellar standards whether or not it has signed an agreement, accepts the claim or knows the ICSS exists. Detection and enforcement remain practical matters.
Tier 3 describes established interstellar civilization: multi-system empires, large trade federations and networked hive-minds with extensive territories and infrastructure. Large-scale terraforming, artificial planetary rings and stellar lifting fall within this level of capability.
These powers sustain major trade lanes and much of the machinery of interstellar politics. They differ greatly in size, government and willingness to comply with ICSS law.
Apex civilizations have moved beyond dependence on habitable planets. Immense artificial habitats and nomadic fleet-worlds can support populations far from ordinary planetary environments, sometimes on journeys between galaxies.
Their manipulation of physical forces and local spacetime exceeds conventional interstellar engineering. They are often distant from routine galactic disputes, intervening chiefly when their own structures or interests are threatened. Their attitudes toward younger civilizations range from paternal concern to indifference.
Ascendant remains a theoretical category. Proposed forms include minds embodied in structures of spacetime or intelligences that have entered higher dimensions. Such proposals describe possibilities rather than verified achievements.
The Gyx are the sole presently identified probable candidate. Enormous artifacts encountered within wormholes have been attributed to them, but their builders and purposes remain uncertain. Those encounters have not confirmed a transcendent species or demonstrated escape from entropy.
The Giza Conventions protect Tier 0 and Tier 1 populations from exploitation and forced subordination. Their ancestry does not remove that protection. Protectorates and client-state arrangements among Tier 2 or higher societies are permitted within the wider framework of interstellar obligations.
“Wellers” is a derogatory name for people confined to their homeworld's gravity well. It appears in interstellar speech as a slur, alongside dismissive uses of “tier-zero.” The formal administrative designation is Tier 0 or Sub-Threshold.