Where the Integration Reaches
// COLONIAL SURVEY: SECTOR ORIENTATION
Where the Integration Reaches

Human space and Vethari space, Year 99 IE. Coverage boundaries are approximate and seasonal.
The Shape of It
Human space occupies a spur of the Orion Arm. Vethari space lies in the Sagittarius Arm. Between them is the Interarm Gap — five to eight thousand light-years of nothing that no vessel either civilization operates can cross.
This is the single most important fact about the map, and it is a fact about absence. Everything reachable is reachable because two civilizations happen to have arisen close enough to the same side of the same emptiness. Everything past that emptiness is not a frontier. It is simply out of range.
The Perseus, Norma, and Scutum-Centaurus arms are known, named, and unvisited.
Four Frontiers
Human expansion did not proceed as a sphere. It proceeded as four pushes along the paths that jump drives made cheap, which is why the map looks less like a territory and more like a set of reaching fingers.

Coverage, Not Territory

The most common mistake a newcomer makes is reading this map as a political one. It is not. The boundaries that matter in the Integration Era are not borders — they are coverage, and coverage is a physical condition rather than a claim.
The Core. Full, stable Integration coverage. An operator's stat line means what it says. Overlay notifications arrive when they should. This is the condition most people in human space have never experienced.
The Fringe. Coverage is variable and unreliable — noisy, not absent. This distinction is the one worth holding onto. The system is present and degraded, not missing. An operator with Signal 12 at a Fringe station may function as though they have Signal 7 to 9 on a moderate day, and 4 to 5 during active Flux conditions. The number on the overlay becomes an estimate, and the estimate gets worse when the weather does. The inner boundary runs through Thaluvor's system.
The Deep Fringe. Beyond formal recognition. Both the Integration and the institutions built on top of it become theoretical. People who want that condition go a long way to find it.
Dead zones. Coverage absent entirely.
Sphere-of-influence mechanics govern how coverage propagates outward from installations. Coverage is not uniform, is not permanent, and does not respect anything drawn on a chart.
How Anything Gets Anywhere
Three propulsion paradigms are in service, and the differences between them shape everything from trade routes to plot.
Jump drive. Recovered from the Architect remnant at Alpha Centauri and reverse-engineered. The backbone of interstellar movement.
Drift. A distinct paradigm, used where jump is unavailable or unwise.
Conventional thrust. In-system.
Fringe multi-drive configurations carry more than one system, because a hull that can only move one way is a hull that eventually cannot move.
And there is no faster-than-light communication with jump. Drift relay beacons carry what they can. Everything else travels at the speed of a ship. This is why packet-ship lines like the Fringe Express exist, and why a captain carrying off-book messages is a profession rather than a favor. On the Fringe, correspondence has a crew.