Green Circuit

Lore & Background

In the sprawling industrial landscape of the alien world, the green circuit is a small, unassuming rectangle of woven copper traces laminated onto a thin polymer substrate. To the player, it is a line item on a production spreadsheet; to the world itself, it is the first whisper of a mind being built from dead ore and ancient petroleum. The copper, pulled from veins that thread through basalt and granite, carries the memory of the planet's molten past. The plastic, synthesized from the black liquid that seeps from deep wells, is a ghost of something that once lived and breathed millions of years ago, now pressed into a flat, green-tinted sheet. The Assembling Machine's robotic arms perform the lamination with a quiet, rhythmic precision—pressing, heating, aligning. In the early hours of a factory's life, the player stands beside a single assembling machine watching green circuits clatter into a buffer, the smell of heated polymer mixing with the metallic tang of fresh copper. It is a small miracle of industry: two humble materials becoming the seed of computation. Every red circuit, every blue circuit, every processing unit, and every advanced circuit that will eventually fill the factory's upper tiers traces its lineage back to this one green rectangle. Fans of the game often describe the moment the green circuit line first goes fully automated as a rite of passage. The factory has crossed from a collection of furnaces and conveyors into a true integrated system, where oil flows alongside ore, where chemistry meets metallurgy, and where the first sparks of electronic logic begin to flicker in the alien twilight.

In Their Own Story

The assembling machine hummed its low, steady note, the one that had become the background music of the last three days. Outside, the sky was the deep amber it always was at this hour, and the distant pumpjacks thumped their mechanical heartbeat into the red dirt. Inside the small workshop the player had built around the machine, the air tasted of warm plastic and hot copper. A green circuit slid into the output buffer. Then another. Then a steady stream, each one identical, each one a tiny green island of woven wire. The player wiped grease from their forehead and watched the input buffers drain—copper wire from the left, plastic bars from the right, both arriving in perfectly timed pulses from the conveyor network that snaked back toward the smelter and the chemical plant. Somewhere downstream, a red circuit was waiting to be born. Somewhere beyond that, a computer. Somewhere beyond that, a processing unit that would make the whole thing look like a child's first drawing. But right now, in this amber-lit workshop, the green circuit was the whole world. And it was enough.

Reader's Guide

Green Circuit is crafted in an Assembling Machine from 1 Copper Wire and 1 Plastic Bar. The upstream chain splits into two parallel tracks. The copper track runs: Copper Ore → Smelting Furnace → Copper Plate, and Iron Ore → Smelting Furnace → Iron Plate; both plates feed an Assembling Machine to produce Copper Wire. The plastic track runs: Oil → Pumpjack → Refinery → Petroleum, which combines with Water in a Chemical Plant to yield a Plastic Bar. Both feeds must arrive at the green circuit Assembling Machine at the same rate. Downstream, each Green Circuit is consumed by: Red Circuit (1 Green + 1 Copper Wire), Battery (1 Green + 1 Copper Wire + 1 Lithium), and Computer (1 Red + 1 Green + 1 Processor, where the Red itself consumes another Green). A single Blue Circuit ultimately requires 2 Green Circuits. As the factory scales toward processing units, advanced circuits, and space-age modules, green circuit demand multiplies rapidly. The typical early bottleneck is the plastic bar line, because it requires an oil infrastructure (pumpjack, refinery, chemical plant) that does not exist in the first few minutes of play. Copper wire is the secondary bottleneck, as iron plate production often lags. Once both lines are automated, the green circuit stage itself rarely becomes the constraint; the bottleneck shifts to the downstream items that consume it. For a 1:1 ratio, maintain equal throughput of copper wire and plastic bars at the assembling machine.

Did You Know?

• The green circuit is the only circuit board that does not require another circuit as an ingredient, making it the true root of the entire electronics tree.
• Because it needs both a smelted metal (copper wire) and a petroleum-derived product (plastic bar), the green circuit is the first item that forces a player to integrate oil processing into their factory.
• A single Blue Circuit ultimately consumes two Green Circuits, meaning the green circuit line must produce twice the rate of the blue circuit line to keep it fed.
• The green circuit's recipe is unchanged from the earliest versions of the game, making it one of the most stable recipes in the entire Factorio catalogue.