the rules, in full
every block is a bet on the one after it.
One tower
There is only ever one tower standing. Every earlier number is a fallen tower, kept forever as an NFT.
Placing
Anybody can add a block. It costs the base price plus a step for every block already standing, so the tenth block of a tower costs more than the first and the next tower starts cheap again. 20% of it is burned (sent to 0x…dEaD). 80% goes into the pot.
The wobble
Every block carries a chance of toppling the tower: 0.1% for every block beneath it. Block 10 has a 0.9% chance; block 60 has 5.9%. The very first block of a tower never falls. The chance is decided by the hash of a block that did not exist yet when you placed yours — nobody can see it coming, you included. Until then, your block is wobbling.
Settling
A wobbling block is decided a few seconds later. Anybody can settle it, and every new block settles the ones under it first. A roll left unsettled for 250 blocks simply stands.
Riders
If you place on top of a block that is still wobbling and it falls, yours falls with it. You rode it down.
The fall
When a block topples, the five blocks standing directly under it split the pot: 40%, 20%, 15%, 10%, 5%, paid in the same transaction. The last 10% (and any share with no block under it) seeds the next tower's pot. The fallen tower's picture is minted, on chain, as an NFT to whoever tipped it. Then a new tower starts at zero.
The wind
After an hour with no new block, anybody may call the wind — free, at most once an hour. A gust topples the tower with a chance of 1% for every hour nobody has built, up to 25%. If it blows the tower down, the top five blocks split the pot as above, and the wreck goes to whoever called the wind. A quiet tower never dies: it only gets riskier, and when it falls it pays.
The wreck
A fallen tower is an ERC-721 drawn entirely on chain from who placed each block — every block is the colour of the wallet that placed it, in every tower. It can be listed and bought inside the contract (95% to the holder, 5% burned, nothing escrowed), or moved like any NFT.
What the contract cannot do
Take ETH (nothing is payable). Send the pot anywhere except to the five under a break and the next tower. Mint a wreck except to a toppler. Change a price, a chance or a share. Pause. Upgrade. The owner key names the token once and is inert forever after.