¶ Megastructures: Ringworld & Dyson Swarm
The two big late-game empire projects in Ferion are the Ringworld and the Dyson Swarm. Both are unlocked through the tech tree, both are paid for in a specific Level 3 ore that's randomly assigned to you at game start, and both reshape what your empire can do — but in completely different ways.
Track and run both from the Resources view (Ringworld and Dyson layers).
¶ Your two assigned ores
At game start, you're randomly assigned a Level 3 ore for each megastructure track:
- One ore is your Dyson Swarm ore.
- A different ore is your Ringworld ore.
- A third ore is your Portal ore.
These three are deliberately disjoint, so the three megastructure paths each demand their own refining chain. Open the Resources view early to find out which ore feeds which — it tells you what your refineries should be producing for the next hundred weeks.
See Resources for the full Level 3 ore list (Ferros Nr.6, Sjampoo, Texorrium).
¶ 
Dyson Swarm
A Dyson Swarm is a per-planet orbital energy farm. Each completed swarm permanently boosts the host planet's stellar energy generation. They stack.
¶ Requirements
- Tech: research Dyson Swarm (Era III). This unlocks the building.
- Building: build a Dyson Sphere Construction Facility on the planet you want to host the swarm.
- Ore: a stock of your assigned Dyson Swarm ore.
¶ How it works
Once a planet has a Dyson Sphere Construction Facility and you have your Dyson ore in your empire stockpile, the planet starts building swarms automatically:
- 1 unit of your Dyson ore is consumed each week.
- Each week adds one swarm to the planet — permanently adding +100 stellar energy generation to it.
- A planet can host up to 5 Dyson Swarms in total. After the fifth, the planet stops consuming ore.
So fully Dyson-swarming a planet costs 5 ore and takes 5 weeks. The end state: an extra +500 stellar energy on that planet, forever (or until it's captured).
Out of ore? The job pauses cleanly that week — no progress lost, no penalty.
¶ Per planet, not per empire
There's no empire-wide cap. Build a Dyson Sphere Construction Facility on as many planets as you like and you'll be paying N ore per week to swarm N planets in parallel. It scales — what scales the cost is how fast you refine your Dyson ore.
¶ Loss
If a planet hosting Dyson Swarms is captured, the swarms stay — but the new owner only gets continued benefit if their own assigned Dyson ore feeds them. (And theirs won't be the same as yours.) In practice, captured Dyson worlds are usually a one-time benefit for the conqueror unless they go to the effort of re-feeding them.
¶ 
Ringworld
A Ringworld is the empire's flagship megastructure — and the only project in the game that consumes an entire star system to make a single, massively powerful planet.
¶ Requirements
- Tech: research Ringworlds (Era III). This requires both Stellar Engineering and Terraforming already done.
- Five planets of your homeworld type in a single star system, all owned by you. Every planet in the system must be yours and must match your homeworld type — meaning you'll usually terraform the foreign‑type planets in a system before starting.
- A stock of your assigned Ringworld ore.
¶ How it works
You enable Ringworld Conversion on each qualifying planet. Each enabled planet consumes 1 unit of your Ringworld ore per week until it has accumulated 3 ore. Once all five (or more) planets in the system have reached the threshold, the system is converted on the next tick.
Total minimum cost: 5 planets × 3 ore = 15 ore + 15 weeks of weekly drip.
¶ What happens on conversion
The conversion is dramatic — and irreversible:
- The closest planet to the star is transformed into a Ringworld. Its planet type becomes "Ringworld", its size resets to Medium, and it gets fresh Level 2 primary and secondary ores rolled for it.
- Every other planet in the system is destroyed.
- All population from the destroyed planets is absorbed into the Ringworld. (This is the only place in the game where you concentrate an entire system's population onto one world.)
- All buildings on the original planet, and the destroyed planets, are gone. The new Ringworld starts with an empty queue and zero buildings — you rebuild from scratch.
- You get a news item announcing the new Ringworld.
¶ The 6× production multiplier
A Ringworld applies a flat ×6 multiplier to production on top of all the usual modifiers (workforce, buildings, planet match, taxes). That makes Ringworlds the only sensible place to attempt the very largest builds — late‑game megabuildings that would take years on a normal world finish in weeks on a Ringworld.
¶ Special building rules
Ringworlds aren't normal planets, and the building catalog reflects that:
- Only Ringworlds can host the very largest combat and mining structures — Halo Barrier, Orbital Singularity Cannon, Temporal Defense Nexus / Laser Array / Energy Nexus, Megastructure Mining Array, Planetoid Excavation Array.
- Ringworlds can't host surface-mining buildings (Ore Harvesters, Astral Drilling Base, Molecular Disruption Mine, etc.) or the Terraforming Command Center — they have no surface in the normal sense.
See Buildings for the placement rules.
¶ Loss
A Ringworld can be invaded and captured like any other planet. The 6× production multiplier persists for the new owner — but their conversion progress on any other worlds in the system resets to zero (those planets were destroyed during conversion anyway). A captured Ringworld is one of the biggest single prizes in the game.
¶ Tips
- Decide early which path to push. Ringworld and Dyson Swarm each demand a different Level 3 ore — going all-in on both at once is twice the refining infrastructure. Most empires pick a lead path and chase the other after.
- Ringworlds need a "Ringworld home system". You're going to terraform every planet in your chosen system to your homeworld type and pour ore into all of them. Picking the right system — well-defended, big planet count, near your core — is half the project.
- Dyson Swarms are the easy win. A single planet, a single building, and a steady ore drip — 5 weeks per planet, no system-wide gymnastics. They're a great early-Era-III pickup while you save up for the bigger Ringworld project.
- Don't start a Ringworld on a front line. You're commiting 15+ weeks of L3 ore drip, then losing every secondary planet in the system. If it falls before the conversion completes, that's all wasted.
- Build the Ringworld-exclusive megaweapons. The whole reason Ringworlds have ×6 production is so the system can pump out a Halo Barrier or Orbital Singularity Cannon in reasonable time. Use it.
¶ Related
- Resources — your assigned Level 3 ores and where they come from.
- Research — the Dyson Swarm and Ringworlds techs, plus Stellar Engineering and Terraforming prereqs for Ringworlds.
- Terraforming — converting a system's planets to your homeworld type ahead of a Ringworld build.
- Buildings — the Dyson Sphere Construction Facility, and Ringworld-only / Ringworld-forbidden buildings.
- Portals — the third Level 3 megastructure track.