Seed stock, the calendar, cleared ground and staples, then water control and fertiliser.
Protect the genetic capital that everything above this tier is built on.
Needs first: nothing — start with bare hands.
Know when to plant, without being told.
Needs first: Start the record (Knowledge)
Turn wild land into a field that does not lose its fertility in five years.
Needs first: Forage, trap, fish, A cutting edge (Tools), Read the year
Grow enough storable calories to stop foraging.
Needs first: Secure seed and breeding stock, Open ground and hold fertility, Read the year
Put water where the crop is, when the crop needs it.
Needs first: Plant staples, Woodworking and the first machines (Tools), Blacksmithing (Tools)
Run the fields as one system: a rotation whose fodder crops feed the stock and whose manure feeds the grain, wet land underdrained so it can be worked and sown, and grain drilled in rows at a known rate and depth so it can be counted and hoed.
Needs first: Open ground and hold fertility, Plant staples, Livestock, Blacksmithing (Tools), Lime (Materials), Brick and tile (Materials)
Put each crop's water at its roots through pipes, in the amount the crop uses, when the soil says it needs it, with every emitter on a line delivering within 10 % of the others.
Needs first: Irrigation and water control, Polymers (Materials), One metre, one kilogram, everywhere (Knowledge), Acids (Materials)
Cross-listed. Its home is Materials & Chemistry › Chemicals.
Pull fertiliser out of the air.
Needs first: Electrochemistry and light metals (Materials), Blast furnace and cheap iron (Materials), Acids (Materials), Petroleum and refining (Energy)
Breed and supply short-strawed, high-yielding cereal varieties with the fertilizer and water they need, and pay their known costs up front: metered groundwater, no highly hazardous pesticides, a gene bank for the varieties they replace, and nutrients bred back into the staples.
Needs first: Synthetic nitrogen (Materials), Drip and sprinkler irrigation, The four-course rotation, field drains and the seed drill
Raise yields on the land already farmed while cutting the nitrogen, water, methane and soil each tonne costs, and stop losing the harvest after it is grown, each change measured on the farm.
Needs first: High-yield varieties, and the Green Revolution's bill, Computing (Computing), Drip and sprinkler irrigation, The four-course rotation, field drains and the seed drill
Every guide, build, reference sheet and book reached from the steps above.
A seed is a living embryo with a shelf life. Kept dry and cold it waits for years; kept warm and damp it dies in a season — and the difference is two rules of thumb and a sealed jar.
Level 1What a soil is made of, why its acidity matters, and how to read a nutrient shortage in the leaves before it costs a harvest.
Level 1Keep the soil covered, feed it, water the roots and fight pests without poisoning yourself: the modern practice that needs knowledge rather than machinery.
Level 1Animals turn grass nobody can eat into milk, meat, wool, leather, manure and traction. They also turn raw milk, a birthing ewe and a dog fed on offal into diseases that kill people.
Level 3Fourteen branches, each with the handful of results a civilization cannot rebuild without, and where to learn the rest.
Level 3Life from the cell up: the human body, microbes and immunity, inheritance and epidemics. Each result with what it lets you do and who first found it.
Level 2North is written in the sky twice a day and all night. Latitude is one angle measured at noon. Everything else is counting paces and not lying to yourself about the count.
Level 3The sky as calendar, clock and compass, then orbits, distances and the universe: each result with what it lets you do and who first found it.
Level 3The two dozen that decide who lives where there is no doctor: what each does, how it spreads, what kills it and which step stops it.
Level 0Surface water is a treatment problem every single day. Groundwater, reached and sealed properly, is a treatment problem once.
Level 3Water in and on the ground, the air and weather, rocks and time, earthquakes and tsunamis, and the climate: each result with what it lets you do and who first found it.
Level 3Turning the sciences into things that work: machines, structures, water in pipes and channels, heat through walls, and feedback control. Each result with what it lets you do and who first found it.
Level 3What matter is made of and how it changes: amounts, gases, acids, the energy and speed of reactions, electrochemistry, and the reactions every industry on the ladder runs on.
A covered tank 1–1.5 m up, a valve, a 120-mesh filter, a 25 mm main and 8 mm dripper lines: drip irrigation for a family plot by gravity, with no pump and no power.
Break the faecal–oral route and return the nutrients — the highest lives-saved-per-effort structure a settlement can build.
Keep a year of grain dry, cool and away from rodents — the single highest-return building on the site.
Cold, damp and dark, without power — how a harvest survives to the following spring.
Drawn overview sheets, each with its corrections printed under it. They orient; they are never the thing you identify from.
