Stonefold

Go is the deepest game ever made from the simplest rules, and Stonefold brings it to your phone against AI you can actually learn on — fully offline.

Place stones on the intersections, surround empty space to claim territory, and cut off your opponent's groups to capture them off the board. Everything that makes Go itself is handled properly: capturing stones with no liberties, the ko rule that stops endless repetition, suicide prevention, passing, and territory scoring at the end to decide the winner. Start small on a 9×9 board where a game takes minutes and the ideas are easy to see, then step up to 13×13 and the full 19×19 as your reading sharpens.

The AI gives you something real to push against, with difficulty levels from a gentle opponent for learning the shapes up to one that will punish sloppy play — and a pass-and-play mode lets you sit across from a friend on a single phone. Legal points are clear, captures play out cleanly, and the final score is counted for you so you can focus on the game rather than the bookkeeping.

Everything runs on your device: no account, no connection, no ads. Just the board, the stones, and the quiet climb toward better play.