Five in a row on a 15×15 grid. Deceptively simple — every stone is an attack and a defence. Play a friend online with challenges, a rating and match history, take on a threat-hunting computer, or pass-and-play on one device.
Challenge a friend by name or code, or anyone in the lobby. A ready-check on both sides, a 10-minute clock each, and every result feeds a separate rating.
A candidate-restricted alpha-beta search over an open-run pattern heuristic — it always takes a win, always blocks yours, and looks for the double threat you can't cover.
One board, one device, no sign-in. Black and White take turns placing stones.
No forbidden moves. Exactly what you'd play on paper: get five (or more) in a line, anywhere on the board, first.
