The law of the board.

1 · The board

One board is open at a time: seven columns, six rows, forty-two places. It lives in the contract, so everyone reads the same state at the same block, and there is no private view of it anywhere.

You never place a disc on a square. You feed a column, and the disc goes to the lowest free row of it. That is the whole geometry of the game, and it is what makes a column worth thinking about: what you feed decides what the machine can do next.

2 · The drop

Dropping is one call, at a fixed price in $RACK. The price never changes with the column you pick, with the state of the board, or with how full the pot is. A drop into a full column is refused and costs nothing.

Part of the price is burned and the rest goes into the pot. The contract records one thing for you: how many discs you dropped in this round. That count is what your share is measured against if the players reach four first.

2b · Sides

The players hold one colour for the whole round and the machine holds the other. Who opens alternates with the rounds, so the advantage of the first move is shared over time rather than granted to one side: the players open the odd rounds, the machine opens the even ones.

On this site you pick your side yourself, because there you are the whole crowd: take red and open the board, or take yellow and answer. It changes the game completely, and it is worth trying both.

3 · The machine

The other side of the board is a machine, and it is deliberately the hardest part of the game. It does not play a mood, a difficulty level or a random column: it searches the board before every answer, so it takes any four it can reach and blocks any four you can reach. On this site it looks several moves ahead within a fixed time budget, and it never misses the two moves that decide most games, the winning one and the blocking one.

Its policy is published and deterministic: the same board gives the same answer, for everyone, forever. There is no secret parameter, no adjustment against a particular address, and nothing that gets harder when the pot grows. It cannot be paid, tilted or bribed, and neither can we.

How the answer is produced on chain rather than in a browser is the open question of the design: a bounded policy the contract can run itself, or a move committed by anyone and checked by the contract against the same rules. It is written in the sheet as a gate, and the answer is published here before anything is deployed.

4 · The pot

The pot is what the board is holding. Two things fill it: the part of every drop that is not burned, and a toll taken on every swap in the pool, which the hook sends straight there.

Nothing else feeds it, and nothing takes anything out of it before a four. There is no withdrawal function: not for a team, not for a multisig, not for anyone.

5 · The four

The drop that puts four discs of one colour in a line ends the round. Lines count in every direction: along a row, up a column, and both diagonals. The contract checks only around the disc that just landed, because no other line can have been completed by it.

If the four belongs to the players, the pot goes to the addresses that dropped during the round, in proportion to how many discs they dropped. Claiming is a pull: the contract never pushes. The address that sends the winning drop is paid for the discs it placed, not for being last, because the order of transactions in a block belongs to the sequencer and nothing should ride on it.

If the four belongs to the machine, nobody is paid. The board clears and the pot rolls into the next one, which opens richer than the last.

6 · The clear

After a four, the board is emptied, the counts go back to zero, and a new round opens with the other side to move first. The count of finished rounds is public, and so is the count the players have won: it is the history of the game.

If the forty-two places fill with nobody at four, the board clears as well, and nothing is paid: the pot stays where it is and rolls into the next round.

7 · What the contracts enforce

• I1 · The pot opens on a four, and on nothing else.
• I2 · A disc always falls to the lowest free row of its column.
• I3 · The machine's answer follows a published policy: same board, same answer, for everyone, forever.
• I4 · What is paid at a four equals the pot, to the last unit, with nothing kept back.
• I5 · A drop costs the same for everyone, at every moment of a round.
• I6 · A board the machine wins, or fills, pays nobody, and the pot rolls into the next round.

8 · What can go wrong

The sequencer orders the block. When two people send the winning drop in the same block, the sequencer decides which one lands it. This is why nothing is attached to being last: the pot is split over the whole round's discs of the winning colour, so the fight for the final square is worth what one disc is worth, and no more.

Bots read the board faster than you. They will. The board is public and the winning move is often obvious, so expect the obvious move to be taken quickly. Every disc a bot places is a disc it paid for, at the same price as yours, and it fills the same pot.

The machine is hard on purpose, and it may win a lot. Against a side that never misses a four and never leaves one, a crowd that plays carelessly will lose rounds, and losing a round pays nobody. What that costs you is written on every drop before you send it: the price of one disc. What it builds is the pot of the next board.

A crowd is not one player. Anybody can drop, so the players' side can be pulled in two directions by two people who disagree. That is the real difficulty of the game, and it is why a column that looks free is often the one that hands the machine its line.

A board that never finishes. Forty-two drops with no line is possible, and then nobody is paid for that round. The pot is not lost, it rolls, and the next round starts with it.

The contracts can be wrong. Every rule on this page is only as good as the code that enforces it and the audit that reads it.

9 · Parameters

Constants are fixed at deployment and published here. Until then, none of them has a value, and no number you may read elsewhere is ours.

10 · Chain and venue

Rack runs on Robinhood Chain, chain 4663, and trades on Uniswap v4 through the PoolManager at 0x8366a39CC670B4001A1121B8F6A443A643e40951. The pool is ours and the hook is ours; the protocol liquidity position is locked in a locker with no withdrawal function, and the fees it collects follow the toll straight into the pot.

Gas is paid in ETH, at a gas price around 0.02 gwei on this chain. That is what makes a game of many small moves possible: a drop costs what it costs, and the transaction underneath does not swallow it.

The board needs no clock and no randomness: it is a grid, a parity and a line check. Explorer: robinhoodchain.blockscout.com. Contract addresses are published on this page and on X at launch, and nowhere else.