Play online
1 · Active ruleset
Two devices, one game. Only moves and hashes cross the wire — the board is never sent. Both sides must be on the same ruleset, or the connection is refused.
2 · How to connect
Both players must use the same method.
The host gets a short code and the guest types it. The introduction runs through the public PeerJS server — a third party. Once connected the game is still device to device: moves and hashes never pass through that server.
3 · Play online
No TURN relay. Some connections — particularly when both sides sit behind strict NAT — will simply fail, and that cannot be fixed from this end.