Documentation

How Cairnheim works

Everything below describes the prototype as it runs today. Numbers are the live values from the game's balance file, not intentions.

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.

The one mistake everyone makes: building far too much before the road network can feed it. A workshop with no delivery is a workshop that holds a worker hostage. Watch the icons above your buildings — ⛔ means unconnected, ⏳ means waiting on an input.

Controls

ActionInput
Pan the cameraRight-click and drag
ZoomMouse wheel (centred on the cursor)
Draw a roadRoad tool, then click-drag across tiles
Select a buildingClick its cairn, not its sprite
DemolishDemolish tool, then click the cairn
SpeedPause · ×1 · ×2 · ×3

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 can be as short as a single tile, and at a junction two cairns may even sit side by side, with nothing between them at all — the same way adjacent flags behave in The Settlers II.
  • 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.

Warehouses are part of the network, not an escape from it. A producer with no customer ships its surplus to storage instead of jamming; a consumer with no supplier draws from it. Both the castle and a warehouse hold 9 999 of each good — a warehouse is not there to give you room, it is there to shorten the walk.

Measured on the engine (a quarry-and-sawmill cluster 50 tiles from the castle, ten simulated minutes): without a local warehouse the trunk cairns sit at 8/8 and only 3 goods reach the castle — the rest is queuing. With one warehouse at the cluster: zero saturated cairns, 48 goods stored locally. Same colony, one building.

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:

GoodPriority 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. A slice of that 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.

ToolRequired by
AxeWoodcutter
SawSawmill
PickaxeQuarry, all mines
ScytheFarm
Fishing rodFisher
CleaverButcher

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:

FoodMealsChain
Meat5Pig farm → butcher (needs a cleaver)
Bread2Farm → mill → bakery (+ well)
Fish1Fisher 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.

Hunger cannot spiral. Morale tracks the share of colonists living in a supplied home, and it only modulates production speed, between 100% and a floor of 50%. Nobody ever starves to death and nobody ever leaves. A famine costs you an hour, not a save file.

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.

ItemCostMade by
Sword1 iron ingot + 1 coalWeaponsmith
Shield1 iron ingot + 1 plankWeaponsmith
Spear1 iron ingot + 1 coalWeaponsmith
Bow1 plankFletcher

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

SoldierKit
Swordsman1 sword + 1 shield
Spearman1 spear
Archer1 bow

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 rune shaft

Every map carries one collapsed shaft it did not build. Restoring it is the long project the rest of the economy exists to serve — the endgame the whole colony works toward.

StageCost to reach itEffect
Ruin—Where every colony starts
Shored30 stone + 30 planksRaises Strike
Awakened200 marble + 200 platinumRaises Strike · unlocks the comfort buildings

Strike is the shaft's output — how much the restored pit brings up, and the plainest measure of how far a colony has come. It is bounded by construction: a bigger figure is a deeper working, built pick by pick and paid for in upkeep, never bought outright.

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. They are the rarest thing in the economy — the prize the harder expedition isles will drop (roadmap).

Comfort closes the same gap, and it is free — the colony earns it by building well. Between them, comfort alone reaches about 14 %; only diamonds go the rest of the way to the floor.

BuildingCostCloses
Chapel40 planks + 40 stone + 60 coins3% of the remaining gap
Bathhouse60 planks + 60 stone + 40 copper ingots + 80 coins5%
Temple80 planks + 80 stone + 30 gold ingots + 120 coins6%

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 the picks were buying, never its monument.

Added StrikePer hour, per 100 StrikeWhy
from the first40 emberwood, down to 12 with Thriftthe fire that drives the shaft
≥ 150+ 70 stone, 14 planksroads chewed up by the hauling; shoring as it descends
≥ 400+ 8 iron ingots, 6 copper ingotstools worn out at the face; pipes for the pumps
≥ 800+ 5 coinswages for the crew

The rule is blunt: digging deeper pays more and costs more, for as long as you dig. That is also the real ceiling — 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, and no amount of coin shortcuts it.

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.

BuildingConsumesProducesCycle
Woodcuttera mature tree1 log6.75 / min measured
Sawmill1 log1 plank13 t · 16.9 s
Quarrya stone deposit1 stone7.67 / min measured
Farmits own fields1 wheat7.8 s per harvest, on its fields
Mill1 wheat1 flour8 t · 10.4 s
Well—1 water13 t · 16.9 s
Bakery1 flour + 1 water1 bread8 t · 10.4 s
Fishera water tile1 fish5.0 s per catch, plus the walk
Pig farm2 wheat + 1 water1 livestock11 t · 14.3 s
Butcher1 livestock1 meat8 t · 10.4 s
Coal minea coal deposit1 coal7.67 / min measured
Iron / copper minethe matching deposit1 ore7.67 / min measured
Gold minea gold deposit1 gold ore5.13 / min measured — longer rest
Copper smelter1 copper ore + 1 coal1 copper ingot34 t · 44.2 s
Iron smelter1 iron ore + 1 coal1 iron ingot41 t · 53.3 s
Gold smelter1 gold ore + 1 coal1 gold ingot45 t · 58.5 s
Mint1 gold ingot1 coin41 t · 53.3 s
Toolmaker1 iron ingot1 tool of your choice8 t · 10.4 s
Weaponsmithsee militarysword · shield · spear22 t · 28.6 s
Fletcher2 planks1 bow66 t · 85.8 s
Charcoal burner2 logs1 emberwood36 t · 46.8 s
Training camp1 colonist + a kit1 soldier15 t · 19.5 s

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

BuildingCostNeedsNotes
Castlepre-placed—HQ · shelters 12 · stores 9 999 per good
Woodcutter2 planksaxe · forest within 8Fells one tree per log
Forester2 planks—Replants every ~16 s within 4 tiles
Sawmill3 planks + 1 stonesaw2 × 2 footprint
Quarry3 plankspickaxe · stone within 8Deposits are finite
Farm4 planks + 1 stonescytheWorks 5 fixed fields around itself
Mill3 planks + 2 stone—
Bakery3 planks + 2 stone—Needs water as well as flour
Well2 planks + 2 stone—No terrain requirement
Fisher3 planksrod · water within 8Waters run dry (10 fish per tile)
Pig farm5 planks + 2 stone—Large footprint
Butcher5 planks + 3 stonecleaver
Mines (coal, iron, gold, copper)4 plankspickaxe · matching deposit3 × 2 footprint
Smelters (copper, iron, gold)4 planks + 2 stone—Lights up while working
Toolmaker4 planks + 2 stone—Made to order
Mint4 planks + 3 stone—The only source of coins
Weaponsmith4 planks + 2 stone—Made to order
Fletcher3 planks—
Training camp5 planks + 3 stone—Large footprint
House6 planks + 3 stone—Shelters 5 · stores 8 meals
Warehouse6 planks + 4 stone—Stores 9 999 per good — shortens trips, not a capacity gate
Explorer hut4 planks + 1 stone—For the expedition mode
Palisade / watchtower1 plank / 4 planks + 1 stone—Free placement, no road needed
Charcoal burnersee in game—Turns logs into emberwood, the mine's fuel
Platinum smeltersee in game—Expedition metal only
Maize farm · Chicken coop · Fish farmsee in game—Second food tier
Kitchen · Provisionersee in game—Cooked meals, worth more than raw food
Geologists' guildsee in game—Trains and sends geologists · 8 coins a survey
Military schoolsee in game—Raises a general's troop cap: 24 basic, 48 premium
Expedition camp · Expedition minesee in game—Placed on expedition islands only
Chapel40 planks + 40 stone + 60 coinsAwakened shaftComfort · one per colony
Bathhouse60 planks + 60 stone + 40 copper ingots + 80 coinsAwakened shaftComfort · one per colony
Temple80 planks + 80 stone + 30 gold ingots + 120 coinsAwakened shaftComfort · one per colony
Rune Shaftpre-placed, in ruin—Restored in three stages

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.

Decorations & attractiveness — temporarily locked

The decorations menu is disabled for now, while the attractiveness loop is reworked. What follows describes it as it will return. In the meantime, population grows only through coin recruitment.

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.

DecorationCostAttractiveness
Signpost1 plank + 1 coin+1
Flower bed2 planks + 1 coin+1
Hedge2 planks + 1 coin+1
Banner2 planks + 2 coins+3
Market stall4 planks + 1 stone + 3 coins+4
Statue4 stone + 4 coins+6
Fountain6 stone + 4 planks + 8 coins+12

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

PropertyValue
Map size156 × 156 tiles (24 336)
Forest cover~18% of the surface
Mountains~12% — stone, coal, iron, gold, copper
Ore per deposit15, then exhausted permanently
Fish per water tile10, then that tile is dead
Tree growth3 stages; only a mature tree can be felled
Simulation tick1.3 s

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.

The full, live quest chain — six acts, eighteen objectives — is generated from the game's balance file on the Guide page, each with its exact reward.

Expeditions

Your home map is permanent, and only you can change it — other players can visit it, never touch it. 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 the endgame prize the harder isles will drop (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.