How Cairnheim works

First ten minutes

You start with a castle, ten colonists, and a stock of planks, stone, food and a starter set of tools. The castle is both your warehouse and your reserve of workers.

1. Place a woodcutter within range of a forest. It does not need to touch the trees — its worker walks out, fells one, and carries the log home.
2. Place a sawmill nearby and draw a road from the castle to both. Every building must touch a road or nothing will ever reach it.
3. Add a forester. A woodcutter with no forester eventually clears the forest and stops for good.
4. Quarry, then food. Farm → mill → bakery, plus a well: bread needs flour and water. A fisher on a lake is the quick alternative.
5. Houses. 6 planks and 3 stone each; each one shelters 5 colonists.

Controls

Buildings are drawn larger than the tile they sit on, so a sprite often overlaps its neighbours. Selection and demolition therefore go through the cairn, which is always exactly one tile.

Transport network

This is the heart of the game, ported from The Settlers. Three objects matter:

• Cairns — the stone markers that stand in for Settlers' flags. Every building has one at its door; you can also place them along a road.
• Roads — the segments between two cairns. A road is at least 2 tiles long.
• Carriers — one per road, and one only. A carrier works its own segment and nothing else.

A good therefore never travels in a straight line to its destination. It is set down on a cairn, picked up by the next leg's carrier, set down again, and so on. Routing picks the cheapest path through the graph — with a penalty for each good already waiting at the arrival cairn, so traffic spreads itself over parallel routes instead of piling onto one.

Congestion

A cairn holds 8 goods. Once it is full, nothing more can be dropped there and the queue backs up along the road. That is the signal to act, and you have four answers:

• Build a warehouse beside the cluster — surplus flows to the nearest storage by network distance, so a local warehouse absorbs it on the spot instead of pushing everything down one trunk to the castle. This is the answer that fixes the cause; the next three fix the road.
• Split the road with an extra cairn — shorter legs, and one more carrier on that stretch.
• Build a parallel route so the router has somewhere else to send goods.
• Move the consumer closer to its supplier and stop crossing the map.

Priorities & distribution

There are two separate settings, and they are often confused.

Distribution — who gets the good

When several workshops want the same good, each one has a slider from 0 to 100 (50 is neutral). The claim is then weighted by what the workshop already holds:

priority = slider ÷ 2units already in stock

The highest priority wins; ties are broken by distance. Because the score halves with every unit delivered, a favoured workshop fills up fast and then automatically hands the queue to its rivals. Setting a slider to 0 excludes a building entirely.

These are the defaults, taken from the original game:

Good	Priority order
Coal	Gold smelter 100 › Weaponsmith 80 › Iron smelter 50 · Copper smelter 50
Iron ingot	Weaponsmith 100 › Toolmaker 70
Wheat	Pig farm 100 › Mill 50

Transport — who gets carried first

A separate ordering decides which good jumps the queue at a saturated cairn. Gems, gold, coins and tools go first; bulk materials like stone and planks go last, on the grounds that they can afford to wait. Full order, highest first:

diamond · platinum · gold ore · gold ingot · coin · axe · saw · pickaxe · scythe · rod · cleaver · wheat · flour · water · tool · sword · bow · shield · spear · meat · bread · fish · livestock · iron ore · copper ore · log · coal · iron ingot · copper ingot · stone · plank

Workers & tools

Every production building needs one colonist to run, taken from your free population. Most of them also need a tool, consumed once when the worker is assigned. No tool, no worker, no production — the building sits there showing its icon.

Tool	Required by
Axe	Woodcutter
Saw	Sawmill
Pickaxe	Quarry, all mines
Scythe	Farm
Fishing rod	Fisher
Cleaver	Butcher

Tools come from the toolmaker, which is a made-to-order workshop: you pick which tool and how many, and it works through the queue. One iron ingot per tool. The castle gives you a starter set, and running out of pickaxes with three mines idle is a normal mid-game crisis.

Woodcutters, quarrymen, fishers and farmers do not stand still. They leave the building, walk up to 8 tiles to the resource, work it on the spot and carry the result back — which is why an over-far placement quietly halves your output.

Population & attractiveness

Houses do not produce colonists — they shelter them. The castle holds 12, each house 5. Colonists arrive in two ways:

• Recruitment. 8 coins buys one immediately — the reason to run the gold chain all the way to the mint. This is currently the only route.
• Immigration — locked. Attractiveness points bring one colonist per 20 accumulated points, provided a bed is free. Its only source was decorations, which are disabled while that loop is reworked — so immigration cannot trigger at the moment.

Population is a hard ceiling on how much you can operate: every workshop holds one colonist for as long as it runs. Expanding means housing, feeding and attracting more of them — three separate constraints that fail at different times.

Food & morale

Each colonist eats one meal every 130 seconds. Foods are not equal:

Food	Meals	Chain
Meat	5	Pig farm → butcher (needs a cleaver)
Bread	2	Farm → mill → bakery (+ well)
Fish	1	Fisher on water — no processing at all

A house stores up to 8 meals as a buffer, and meals rotate across whatever foods it holds — a varied larder lasts longer than it looks. Measured on the engine, deliveries included: one bakery feeds about 13 colonists on bread alone, and past a dozen bakeries bread stops scaling — the carriers saturate before the ovens do. Big villages eat meat.

Morale moves slowly on purpose — a smoothed average that takes 30–40 seconds to respond, so one house briefly running dry doesn't make the whole colony stutter.

Military

Weapons are the last sink of the iron chain. The weaponsmith is a made-to-order workshop like the toolmaker — you choose what it forges.

Item	Cost	Made by
Sword	1 iron ingot + 1 coal	Weaponsmith
Shield	1 iron ingot + 1 plank	Weaponsmith
Spear	1 iron ingot + 1 coal	Weaponsmith
Bow	1 plank	Fletcher

The training camp turns a free colonist plus a kit into a soldier:

Note the trade-off: every soldier is a colonist who has stopped working. An army is paid for in production, twice over — the iron it consumes and the labour it withdraws.

The Cairn Mine

Every map carries one collapsed shaft it did not build. Restoring it is the long project the rest of the economy exists to serve, and it is the only thing that mints $CAIRN.

Strike is your mining power, and the only thing that sets your share. The network mints a fixed amount per day and splits it by Strike: your share is your Strike over the whole network's, yours included. The pot does not grow when players arrive — the slices get thinner. Emission is bounded by construction, not by attendance.

That divisor has a floor. Pro-rata splitting has a blind spot: on an empty network the divisor collapses and a handful of players would take the entire pot. So shares are divided by at least the floor, however few miners are actually online — and whatever nobody claims is not redistributed, it stays in the reserve for the players who arrive later. It costs a regular player nothing; it stops the first fifty accounts from quietly accumulating several percent of the supply while the token is still worth nothing.

Thrift — the emberwood sink

The base shaft burns nothing and never stops. Every pick you set beyond it eats fuel: 40 per hundred strikes at first, down to a hard floor of 12. You buy that efficiency two ways — diamonds, and comfort.

Diamonds are set into the wellhead and never consumed: each one closes 8 % of whatever gap is left down to the floor, so the twentieth still helps and none is ever wasted. Prise one back out and it returns to you intact, free to sell. They are bought with CAIRN, at a price that follows your own Strike — a bigger shaft saves more from the same stone, so it pays more for it. The harder isles will drop them too; that part is on the roadmap.

Comfort closes the same gap, and it is free — the colony earns it by building well. Between them, comfort alone reaches about 22 %; only diamonds go the rest of the way to the floor.

One of each per colony, all three locked until the shaft is Awakened. They are the reason the copper and gold chains keep going past the toolmaker.

Upkeep — what a pick actually costs

A pick is not paid once. It raises Strike, and Strike is billed to the colony every hour, for as long as you run it. Emberwood alone at first; then the bill widens as the shaft goes deeper. Thresholds are on added Strike — the free base shaft is never charged, so a colony that runs dry loses the yield its rig was buying, never its monument.

This is the ASIC-to-electricity relationship: mining more pays more and costs more. It is also the real ceiling on a rig — 100,000 Strike would demand 40,000 emberwood an hour, more than 520 charcoal burners running flat out, fed by some 260 woodcutters. No colony can feed that, which is why capital cannot simply buy the pot.

Production chains

One tick is 1.3 seconds. Workshops have a fixed cycle, listed below and measured on the running engine. Extractors do not: their worker walks to the resource, spends 2.2 s on the spot and walks back, so their rate is set by distance, not by a timer. The figures given for them are the measured maximum with the deposit at the building's foot — placing a mine 8 tiles from the rock face instead of 4 costs half the output.

The three smelters run at deliberately different speeds — copper fastest, gold slowest. Coal is the shared input for all of them and for the weaponsmith, which is why coal priority is the most consequential slider in the game.

Buildings

Buildings need one clear tile between them, and the door tile — south-east by default — must stay free for its road and cairn.

Goods

Forty-one goods circulate on the network.

Log

Plank

Stone

Wheat

Flour

Water

Bread

Fish

Livestock

Meat

Coal

Iron ore

Copper ore

Gold ore

Iron ingot

Copper ingot

Gold ingot

Coin

Axe

Saw

Pickaxe

Scythe

Rod

Cleaver

Sword

Shield

Spear

Bow

Diamond

Platinum

Maize

Egg

Cooked meal

Copper pickaxe

Spyglass

Ration

Mine kit

Marble

Platinum ingot

Emberwood

Cairn pick

Decorations & attractiveness — temporarily locked

Decorations are placed instantly, need no road and no worker, and are paid for out of stock. They all cost coins as well as materials — that is what the gold chain is ultimately for.

Small pieces are deliberately the worst value per coin. Twenty points of attractiveness is one immigrant — the fountain gets you there in under two.

World & resources

Nothing renews itself, and nothing is beyond renewal either — each resource has a trade whose job is to put it back. A forester replants what the woodcutter fells. A fish farmer returns fish to the lake the fisher emptied. And an exhausted stone, coal or ore deposit is reopened on the spot by a geologist, refilled to a full seam rather than patched, so sending one is a decision and not a chore.

The pressure that eventually pushes you off your starting ground is therefore not scarcity — it is labour: every renewal costs a worker, a walk and a wage. What no trade can produce at home is platinum, which exists only on the expedition isles.

Drawing a road through a forest clears the tree in its way. Convenient, and a slow way to ruin a woodcutter's district if you are not paying attention.

Quests

A chain of objectives guides the early game. Each reward is a choice: materials to reinvest, or coins.

Expeditions

Your home map is private and permanent. Expeditions are the opposite: instanced maps you travel to, strip of what they hold, and leave.

• Explorers trained at the explorer's hut bring back charts to new sites.
• Rare veins — marble and platinum — exist only out there, mined by a single all-purpose expedition mine. Diamonds are not mined on the two starting isles: today they are bought with CAIRN, and the harder isles will drop them (roadmap).
• Camp defences: palisades and watchtowers, placed freely with no road and no worker, to fence off a temporary dig.

Geologists are the other half of it, and the thing they do that matters most is not surveying — it is reopening. Send one to a worked-out stone, coal or ore deposit and, after about five minutes of digging on the spot, the seam is back to a full reserve. Not topped up: full. A deposit refilled to a third would just mean sending another geologist straight after, and the mechanic would become a chore instead of a decision.

Recruiting one costs 40 coins and a copper pickaxe — dearer than a general, because a general spends resources and a geologist creates them. Each mission then costs 8 coins: a rent on a repeated action, not a barrier. They carry their own skill tree, capped at 14 points, so no two end up identical and specialising by ore actually means something.

Islands, landings, bandit camps and the fight are all in the game. What is still moving is the balance of the loot they pay out.

Ownership — in progress

A headless copy of the engine already runs on our own server and re-checks what every client reports. It is live in shadow mode: it logs disagreements and sanctions nobody. It becomes the ledger that counts before any real value moves — which is also why the player-to-player market is not open to strangers yet.

• Land as NFTs — limited supply, devnet first. A developed map is worth what someone will pay for the hours in it.
• $CAIRN — a utility token with capped, decreasing emission. Spent on premium crafting and burned by it. Not handed out for playing.
• Marketplace — player to player, with a fee that funds the studio. That fee is the business model: it depends on activity, not on new arrivals.
• Guardrails, written into the contracts — emission cap, a sink for every faucet, a ceiling on offline production so bot farms are pointless, and no pay-only gameplay advantage.

The reasoning behind this model →