Cairn
Original · a stacking duel for two
The stack belongs to its top stone, whatever it is standing on.
Ready to play now.
A demonstration of Cairn, played by the computer against itself.
Cairn — playing itself
Ways to play
Alone, against the computer
Your own pace, no arranging anything. Take a move back whenever you like.
Play alone5 opponents, weakest first
- The DrifterWanders, and avoids the shoulder entirely — it has been told the hill is dangerous and believed it. No evaluation at all: the seed picks among the carries that shed nothing. 2.3 stones kept a hill and 27 of 240 hills against the Keeper.
- The KeeperCounts its HAND and nothing else: enemy stones this carry sheds, less its own stones lost to the scree, with a nudge for landing on its own top. One number, no hillside. 211-29 over the Drifter, z=11.7, and 4.4 stones kept a hill.
- The ReaderThrows the hand-count away and reads the whole HILLSIDE a carry leaves — tops owned, stone standing under them, enemy stones buried, its own stones buried — with the hands weighted a hundred to one because six of them ends it. 240-0 over the Keeper, z=15.5. On this hillside, reading the stone is not a tactic, it is the tactic.
- The AnswerThe Reader’s evaluation searched one reply deep. It stops asking what a carry gives and asks what is left after the other walker has taken their best of it. 192-48 over the Reader, z=9.3 — the rung this card used to call dead even.
- The Long LookThe same evaluation three plies out — carry, reply, answer — so it sees both the shed it sets up and the shed that punishes it. 182-57 over the Answer (z=8.1) and 240-0 over the Drifter. Six stones kept a hill, all 240 hills, and the shortest hills on the shelf at 19 plies.
Together, in the same room
2 players. One device goes round the table, or everybody plays off the same screen.
Play in the same roomOnline, at a table
A room code, joinable from anywhere. Pause tonight and pick it up next week from your device.
Play online
About
A 5×5 hillside of stacked stones, dealt fresh from the seed — twelve stones a walker, so the six kept stones that win are exactly half of what the other one brought. One law with teeth: a stack belongs to whoever’s stone sits on top of it, however deep it stands. Carry the top stones of a stack you own — one, two, three, four — in one straight jump EXACTLY as many squares as stones you carry, and set them down on anything. No stack stands higher than four: the shoulder sheds the BOTTOM, an enemy stone that falls is yours to keep, a stone of your own is lost to the scree. Let TWELVE plies pass with nothing falling and the shoulder is owed: a walker who can shed must, and the quiet carries stop being legal. Buried with nothing to carry, you dig. First to keep six enemy stones has the hill.
How it feels
- Cold stone, warm hands
- A tower four high with your colour on it
- Digging all afternoon
What the design is for
The top stone owns the stack
However deep it stands, whoever’s stone sits on top can carry it — and nobody else can. The whole game is played over that one law: bury their tops, raise yours, and remember that a tower is only ever one landing away from changing hands.
Carry exactly what you lift
One stone moves one square; three stones move three. The arithmetic is the game’s spine — the tower you want is exactly as far away as it is tall, and splitting a stack leaves the rest standing where it stood.
The shoulder sheds the bottom
No stack stands higher than four. A landing that goes over sheds from the BOTTOM — what fell was standing there before you arrived — and the colours do not matter to the fall: an enemy stone is kept, a stone of your own is scree. Six kept enemy stones win the hill.
The shoulder is owed
Twelve plies with nothing falling and a walker who CAN shed must — the quiet carries simply stop being legal. It was added because the hill had no ending a capture decided: two careful walkers shed nothing, ran the 160-ply cap and were separated by a tie-break. Now 240 of 240 hills between thinking walkers end on six kept stones, and none of them reach the cap.
The dig
Buried with nothing to carry, a walker prises one enemy stone off the top of any stack — to the scree, kept by nobody. A whole turn for one stone: slow, and the only way back out of a burial. It is why this game cannot be won by burying alone.
A hill laid by its seed, and laid even
Every hillside is dealt from the seed and dealt fair: twelve ivory stones and twelve coral, so the six kept stones that win the hill are exactly half of what the other walker brought. The first carry is worth nothing measurable — the top rung against itself takes 121 hills as first walker and 119 as second, which is z=0.1.
Taught carry by carry
Eight steps: the carry, the top, the split, the shoulder, the scree, the dig, the shoulder’s due — and then the whole hillside to yourself.
- Best at
- 2
- Kind
- Strategy
- Table
- Competitive
- Studio
- Board.game Originals
The opponents
The Drifter
Wanders, and avoids the shoulder entirely — it has been told the hill is dangerous and believed it. No evaluation at all: the seed picks among the carries that shed nothing. 2.3 stones kept a hill and 27 of 240 hills against the Keeper.
The Keeper
Counts its HAND and nothing else: enemy stones this carry sheds, less its own stones lost to the scree, with a nudge for landing on its own top. One number, no hillside. 211-29 over the Drifter, z=11.7, and 4.4 stones kept a hill.
The Reader
Throws the hand-count away and reads the whole HILLSIDE a carry leaves — tops owned, stone standing under them, enemy stones buried, its own stones buried — with the hands weighted a hundred to one because six of them ends it. 240-0 over the Keeper, z=15.5. On this hillside, reading the stone is not a tactic, it is the tactic.
The Answer
The Reader’s evaluation searched one reply deep. It stops asking what a carry gives and asks what is left after the other walker has taken their best of it. 192-48 over the Reader, z=9.3 — the rung this card used to call dead even.
The Long Look
The same evaluation three plies out — carry, reply, answer — so it sees both the shed it sets up and the shed that punishes it. 182-57 over the Answer (z=8.1) and 240-0 over the Drifter. Six stones kept a hill, all 240 hills, and the shortest hills on the shelf at 19 plies.
Achievements
0 of 5 earned
The Hill Is Yours
Win a hill of Cairn.
Double Fall
Keep two enemy stones with one landing.
Four High
Stand a tower at the shoulder with your stone on top.
The Split
Carry part of a stack and leave stones standing behind.
Clean Hill
Win six keeps to none.
Key art
Key art — Board.game art system
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