
Tick Tock, Next Block
Haul mempool transactions to the miners through the bulls’ and bears’ price war. Hug the live price front to score; the best run takes the pot.
Decentralized games and markets. No custodian. No central operator.
Play. Build. Run a node. Earn fees.
Race the next block, outguess a rival, or call the price. Every game runs on Bitcoin testnet4 with free test sats: real nodes, real federations, real Lightning, nothing to lose.

Haul mempool transactions to the miners through the bulls’ and bears’ price war. Hug the live price front to score; the best run takes the pot.
Rock Paper Scissors for bitcoin. Both players commit a hidden move, then reveal it; the winner takes the pot, a draw returns both stakes.
Will the bitcoin price be higher at the end of the 15-minute window? Pick Up or Down; the attestors sign the price and the winning side shares the pot.
Pay a Lightning invoice. Your sats arrive in the browser wallet as e-cash of a federation.
Join a round. Your stake is locked in the federation, not paid to an operator.
The round's committee of nodes replays the runs or checks the signed price. 5 of 7 must sign the same result.
Winnings land back in your wallet. Withdraw to any Lightning wallet.
Rounds run on independent nodes. Any bonded operator can host them; no company runs the game.
Your stake is locked in a federation, not paid to an operator. No single party can take it.
Nodes replay every run. A result counts only when 5 of the round's 7 seats sign the same one, and anyone can object for 10 minutes.
Every node posts a bond and a signed advertisement on Bitcoin. Your browser finds the nodes there and checks them itself.
No sign-up, no email, no password. Log in to play with your Nostr key, restore your wallet from it on any device, pay from your own wallet over Nostr Wallet Connect, and run a node with the same key.
Nostr in the docs →An nsec, a NIP-07 browser extension, or a NIP-46 remote signer: a bunker link or a QR code for your phone signer.
Your game wallet's seed is kept on Nostr, NIP-44 encrypted to your own key (NIP-78). Log in anywhere and it is back.
Connect your Lightning wallet once (NIP-47) to pay deposits and stakes, and to withdraw winnings into it.
Node owners claim and manage their node with a Nostr key. With an extension or remote signer, every owner action is a signed NIP-98 event (kind 27235) the node checks.
relay.bitcoin-arena.io keeps profiles, relay lists and encrypted seeds, and carries remote signing and wallet requests. Nothing else.
The Bitcoin Arena community lives on Armada, a Nostr chat app. Join with the same key.
The split is fixed. An item pays 40% to the nodes and 20% to the protocol reserves, plus the developers’ share you choose.
2 % of every paid round and 20 % of every item go to the protocol reserves, locked to each federation’s 5-of-7 key. Anyone can propose a payout; it is paid only if the bonded nodes vote for it. Read and discuss the proposals →
Write it and sign it, and any node can host it. The nodes replay every round with your rules. No approval, no listing fee.
Build a game →Pick a question and its outcomes, and name who signs the result. Paying out the winners is built in.
Build a market →Post a bond, take a seat, host games, sign results and earn a share of the fees. Manage it from the owner area.
Run a node →One package for your system: Node.js, the node, the installer, cloudflared and Tor. It opens a small window that walks you through the setup in your browser, on testnet4.
Windows 10 and 11, 64-bit. Installs into your user folder, no administrator.
Drag Bitcoin Arena to Applications; the first time, right-click it and choose Open.
Debian, Ubuntu and their kin: sudo apt install ./bitcoin-arena-node_*.deb. Any other: the plain archive.
How to install, set up and update it: Run a node in the docs. Every file is in the release's SHA256SUMS, signed with the Arena release key. The source: all repositories.
Every node posts a bond on Bitcoin. No bond, no seat.
Each round's committee is drawn from the bonded nodes by a Bitcoin block hash.
Games are deterministic. Nodes re-run every input and sign the result.
Stakes lock in a Fedimint federation whose guardians are the nodes, never in one company's wallet.
Payouts and withdrawals move as sats over Lightning.
The Arena is live on Bitcoin testnet4: all three games, both federations, all fourteen nodes. Test sats have no value, so you can try everything without risk.
testnet.bitcoinarena.io