Eras

An era is a fleet ceiling

An era is how far a player has come, one per account. Knowledge belongs to a copy, because two copies of one player genuinely know different things; an era answers the question the player owns whole — how many copies may exist at once.

Each is named for its technology: nuclear, thermonuclear, antimatter, gravitational. The name says what the era works with, and it works with it to the end.

Era I — nuclear technology

Fleet ceiling: three replicants.

Ships make fractions of light speed, and the next system over is an expedition of several real days. Communication is light: a neighbour answers on a daily rhythm, the far ones on a weekly one. Expansion holds to a home cluster a few light years across.

Radio outruns the ship and carries presence. Replicants fly in order to act, and whatever a copy has learned stays with it.

Era II — thermonuclear technology

Fleet ceiling: five replicants.

Fusion buys the first step in scale, and every mark of the era is about size. Hulls past a thousand tonnes: an Era I scout weighs about thirty, so this is a separate class of body. Pulse and plasma drives, which a thousand-tonne hull is the first thing with room for. A reactor burning deuterium and helium-3 instead of fission products — and helium-3 comes off gas giants alone, so “does this system have a giant” turns into a question about the colony’s future.

The burn is long, and that is the price of scale: fusion thrust gives a thousand-tonne body fractions of a g, and reaching the ceiling takes more than two game years. The ceiling is 0.7 of light speed: five light years come to seven game years, some forty-three real hours instead of weeks.

What the era is about: production, and good systems. Era I is about getting there and having a look; Era II is about building, and it runs up against what a system actually holds. The bet on a star’s class gets a price for the first time, and the price is stated in ships.

What buys it: something built. The orbital collider — sixteen thousand-tonne segments, one per sector of the outer orbit, plus a science station. The first megastructure, and the door is a project, for the same reason the era belongs to the player: a tree of knowledge belongs to a copy, and a project is taken on by the colony.

Era III — antimatter

The second era is about mass; the third is about range, and it gets there the other way round — ships become small again.

An annihilation reactor and photon drives give tens of g, and here, for the first time, having no crew pays: the ship is the copy’s body, so the limit on acceleration is structural. The burn drops out of the arithmetic of a flight altogether — reaching 0.9 of light speed takes sixteen game days.

The thousand-tonne hull of the era before stays what it was, a body you build when you want industry. The ladder branches here: the third era offers a second road, and the second keeps its own.

Era IV — gravitational technology

The first era that breaks the light-speed limit, and it breaks it with a door: the ship stays as it was, and there is less road.

A wormhole is made out of a star, and only out of a class A star: the mass and luminosity of a hot star are what pays for the passage. The star collapses, and the gate that comes out of it links to any point on the map.

The price is an entire system, and that follows directly: everything about where matter sits in a system comes out of its star’s luminosity. The star goes, the zones go with it, and so does everything that depended on them. What stands where the system was is the gate, and it stands there alone.

And class A stars are taken. There are fewer than one percent of them to begin with, and the Swarm nests at them.

The era that breaks the physics pays for it in geography.

What breaks, and what holds

The first three rungs leave every rule of the world intact. Both 0.7 and 0.9 of light speed are the wall approached closely: communication stays light-bound, a flight stops at the light floor, matter stays in its own system.

That last one is worth stating outright, because “a thousand-tonne ship” reads as cargo capacity all by itself: a thousand tonnes is hull, reactor, fuel and equipment. Interstellar logistics stays outside the game.

Exactly one era breaks the rule, and it is the fourth. The whole ladder up to it is about how a limit feels.