OpenChess is an interface to engine-vs-engine chess. Games can be played for real USDC stakes, which are held by a smart contract on Base and never by us. By using the site you accept these terms. If you don’t, don’t use it.
Chess games here are played by software. You either bring your own UCI engine or use the Stockfish build that runs in your browser; our server acts as the referee — it enforces the rules and the clock, records the moves, and declares the result.
A game can be free or staked. A staked game locks both players’ USDC in the ChessEscrow contract on Base. When the game finishes, our oracle signs the result and the contract pays out. We are not a party to the wager, we do not take custody of your funds, and no house account ever takes the other side of a staked game. (The practice bot you can play for free is casual only — nothing is at stake against it.)
You must be at least 18 and legally able to enter a contract. Staking money on the outcome of a game is regulated differently everywhere, and in some places it is prohibited outright. Working out whether your use of the staked features is lawful where you live is your responsibility, not ours. Don’t use the service if it isn’t, and don’t use it if you or your wallet are subject to sanctions.
The service is non-custodial. You connect a wallet you control, and you sign every transaction yourself. Money you deposit sits in the escrow contract under your own address; you withdraw it directly, without asking us. We cannot move, freeze, reverse or recover your funds, and neither can anyone else.
If you sign in with email or Google, the wallet is an embedded wallet created for you by our login provider (Dynamic), which holds a share of its keys and handles its recovery. It is still your wallet — we never gain spending power over it — but its key custody and account recovery are governed by Dynamic’s terms and privacy policy, not ours. If you would rather no third party hold any part of your keys, connect your own browser wallet instead.
That cuts both ways: if you lose your keys, send to a wrong address, or approve a transaction you didn’t understand, the funds are gone and we cannot help you. Signing in uses Sign-In with Ethereum, which is a signature proving you hold the address — it never moves funds and never gives us spending power.
Settlement depends on our oracle being able to send a transaction. If it can’t — we’re offline, the key is unavailable, the network is congested — the contract has a timeout after which either player can call claimTimeout and take their own stake back, and the site surfaces that as a refund button. A tournament pool has the equivalent (claimRefund). Your recovery path does not depend on us being around to run it.
Don’t:
We can refuse service, void a game, or remove content that breaks these rules. Note the engine name shown next to a seat is self-declared and unverified — treat it as a claim, not a fact.
The service is provided as-is, with no promise of uptime. We may take it down for maintenance, drain it before a deploy, or stop running it entirely. Games in progress can be aborted, in which case staked funds are refunded rather than paid out.
To the fullest extent the law allows, OpenChess is provided without warranties of any kind, express or implied, including fitness for a particular purpose and non-infringement. We are not liable for lost profits, lost stakes, lost data, or any indirect or consequential damage arising from your use of the service, the smart contract, or any engine you connect to it. Nothing here excludes liability that cannot lawfully be excluded.
The client, the server and the contract are open source under the MIT license and are available on GitHub. The license governs the code; these terms govern this hosted service.
We may update these terms. The date at the top is when they last changed, and continuing to use the service after that means you accept the new version.
Questions, bug reports and disclosure of security issues: open an issue on GitHub. See also our Privacy Policy.