Play the Chain

Stockfish, compiled from C++ with icpp-pro, running inside an Internet Computer canister.
⛳ New: Chain Golf All games & cycles →

What is Stockfish? The strongest open-source chess engine in the world, and for years the reigning computer chess champion. Grandmasters use it to analyse their games; no human has a realistic chance against it at full strength. It's over 12,000 lines of performance-tuned C++. What's new here: that whole engine was compiled to WebAssembly and runs inside a smart contract (a canister on the Internet Computer). Every move it plays is computed by 13 independent machines that must agree on it, with no server behind it.

Start a game. The canister will referee it.
Moves · tap one to replay it and see its receipt
⛓ On-chain view

What happens when you move

Left: what it means. Right: what actually runs, for the technically curious.
⛽ Fuel the chainall games & cycles →

Everyone plays on a shared tank of cycles

Every move the chain thinks of is paid in cycles from the canister's own balance. Anyone can top up the tank with ICP, and the canister turns it into cycles itself, through the IC's cycles minting canister. Nothing is bought for you alone: the fuel keeps the game free for everybody.
In the tank
–
 
  1. Send ICP from your funnAI wallet, the NNS app or any ICP wallet, to the canister's principal:
    ne5l7-xiaaa-aaaaj-qsm3q-cai
    From an exchange, use its account ID:
    460d1214503541468865ef7728ed17cf6e232585e6898a8d1626230ffa8e2cc7
  2. Press Refuel. The canister finds the ICP and turns it into cycles.

Nothing here runs on a server. The page, the rules and the engine all live in one canister: it checks your move, runs a single-threaded Stockfish 11 search inside the 40B-instruction limit of one message, and writes both moves to its stable memory. The game record can't be edited afterwards.