The rules to get you started
In brief
The app offers boards with 9 × 9, 13 × 13 and 19 × 19 intersections. The initial size is 9 × 9. Black plays first; each player places a stone on an empty intersection or passes. Once placed, a stone does not move.
The board and turns
The app offers boards with 9 × 9, 13 × 13 and 19 × 19 intersections. The initial size is 9 × 9. Black plays first; each player places a stone on an empty intersection or passes. Once placed, a stone does not move.
Liberties and captures
Empty intersections adjacent horizontally or vertically are liberties. Stones of the same color connected in this way form a chain. A chain with no liberties is removed from the board. Diagonals do not connect stones.
Suicide and repetition
In this app, a move that leaves your own chain without any liberties is forbidden. The board position cannot repeat an earlier position: this is positional superko.
Ending and scoring in the app
Two consecutive passes end the game. Area scoring adds together the stones on the board and the empty intersections surrounded by only one side. White receives a komi of 6.5 points. The app does not offer a manual phase for removing dead stones.
A situation to observe
In the diagram, the white stone is at B1. The black stones at A1 and B2 take away two of its liberties. C1 remains: if Black plays there, the white stone is captured.