On the chain
Not because it sounds impressive. Because a chess rating is a claim about the past, and a claim about the past is exactly the kind of thing a chain is good at holding.
The argument
On every chess site you have ever used, your rating is a number in a table that somebody else can edit. Usually nobody does. But you cannot check, you cannot take it with you, and if the site closes it goes with them.
ITZA Chess moves the referee. In a rated game the contract validates every move from both players, decides the result itself, and writes the rating change. There is no function anywhere that lets a client say "my rating is now this". Not for you, not for us.
The side effect is the nice part: because the record lives with your wallet rather than with an account on a server, it follows you. Sign in on a borrowed laptop and your games and your rating are already there.
A game played entirely in the browser is practice. It is saved, it is labelled, and it counts for nothing - by design.
One move, in detail
Your move is packed into a single sixteen-bit value - from square, to square, and what happened - and signed by your wallet. Small enough that one move can afford to be one transaction.
The contract runs the same Rust rules engine your browser runs. If the move is not legal in the stored position it is rejected and the game state is left exactly as it was.
The game object updates and the block settles, which the cluster does in about a hundred milliseconds. Both players subscribe to the game wallet, so the write wakes them and the nodes push the new position from there.
Mate, stalemate, resignation, an accepted draw, threefold repetition or a claimed timeout: the contract decides, computes the rating change and files the game to both players' histories.
Time is projected from the chain's record of when each move landed, so both players read the same clock. Increment is applied by the contract. A fifteen-second grace after the flag keeps a dropped connection from being an instant loss.
If your device and the chain ever disagree about the position, the client discards its copy and replays the game from the chain's record. There is no negotiation, and you generally will not notice it happen.
Because each move is its own transaction, the game has a move-by-move record with real timings attached - which is the raw material for the fair-play work coming next.
The part that should not be possible
A chess server can be fast because one company owns one machine and that machine decides what happened. A blockchain is slow because nobody owns it and everybody has to agree. ITZA settles a block in about a hundred milliseconds, which means you get the second thing at the speed of the first.
Not a block time, not an optimistic confirmation you are asked to trust while the real one catches up. The move is validated, applied, recorded and pushed to your opponent inside that window.
Plenty of games put a scoreboard on a chain. Here the chain IS the referee: each move is a transaction the contract validates against the rules before it is allowed to exist.
The app is not a website with a chain bolted on. The pages, the engine and the board come off the same cluster that referees the game. There is no game server in the middle to fall over or quietly decide something.
One-minute chess is the honest test, because at that speed nothing can hide. Most chains cannot referee a bullet game at all - by the time the move is final the clock has moved on. On ITZA the move lands, settles and reaches your opponent inside the same block, so a rated bullet game against a stranger feels like a local one and is still refereed end to end by a contract.
That is the claim worth checking, and it is the one this whole project rests on: a decentralised system running at the speed people expect from a centralised one.
| Network | Settlement | Notes |
|---|---|---|
| ITZA | about 100ms | What ITZA Chess runs on today |
| Sui | under 400ms | Owned-object transactions, which skip full consensus |
| Aptos | about 1s | BFT consensus, final at each block |
| Cosmos chains | 1 to 6s | Tendermint, final at each block |
| Solana | about 12.8s | Alpenglow targets 150ms, but it is still in testing and not on mainnet |
| Ethereum | about 13min | Deepest economic security of any chain |
| Bitcoin | about 60min | Six confirmations |
These are published figures as of mid-2026, and on settlement ITZA leads every one of them. The nearest competitor is not close: Solana finalises in about 12.8 seconds on mainnet today. Its Alpenglow rewrite targets 150 milliseconds, and even that target does not beat what ITZA already does.
That is the whole point of the section. This is not a chain that will be fast enough one day. It is refereeing bullet chess, move by move, right now.
Ratings
Beating a machine is not the same as beating a person, and neither is spotting a tactic, so the three are not mixed into one number. All three are awarded by the contract and none of them can be touched by your browser.
ai_move transaction.
Earned in rated online games against people. This is the ladder that counts, and the only one most players will care about.
Earned against the Challengers in Normal mode only. The contract plays the machine's side, so it referees the whole game. Learner and Offline never touch it, and no ladder is ever touched by another.
Earned solving tactics in Normal mode. The contract holds the position and the answer, hands out the one and checks the other, which is what separates this from a tactics score kept on somebody's server.
A standard Elo calculation, done in whole numbers rather than floating point so that every node computing it arrives at exactly the same answer. Both ratings start at 1200 and move by a K-factor of 24, which means two evenly matched players swap twelve points on a decisive game.
The app shows all three ratings everywhere they matter: on the account chip, in the settings profile, on the end-of-game panel, which says which ladder just moved, and on every entry in your history. A rating the app has not loaded yet shows as a dash rather than a made-up 1200.
After a rated game the client watches the chain until the new rating lands, so the winner sees the change without reaching for refresh. The number stored on the chain is the real one; the copy on your device is only a cache of it.
Your account
Sign in the way you already do everywhere else on ITZA: scan the code with your ITZA Vault and confirm the six digits, or use a username and password, or bring a wallet you already have.
A username and password does not create a record on our server - it derives your key. Same name and same key means it is you. Same name with a different key means the password is wrong, and you are told so plainly rather than being signed into somebody else's name. A name nobody holds is registered to you there and then.
Advanced users can generate a raw wallet with a recovery phrase and a key file, or restore one they already keep. And a key that belongs to a different cluster is turned away at the door rather than producing a session that looks fine and quietly does nothing.
You are a public key. Your games, your two ratings and your history are attached to a wallet, not to a name and an email address on somebody else's machine. Change device, keep everything.
Roadmap
Written plainly, including the parts that are not finished. The cluster is live and two-player games already run on it move by move.
Staking is not enabled and free play does not depend on it. Nothing here is an offer or an invitation to invest; see the disclosure document.
Built as an ITZApp
The app is an ITZApp: it is served from the chain, talks to the node over a single WebSocket, and makes no third-party requests at all. No content delivery network, no font service, no analytics, nothing that could disappear or watch you.
There is one deliberate exception to the on-chain rule, and it is in your favour: if the chain library fails to load, the app still starts. Games against the computer, pass & play, the lessons and the analysis board all keep working. Only online play needs the chain.
Play a rated game and watch the result get written by something other than the browser it was played in.