Go originated in China more than two and a half thousand years ago and developed a profound tradition in Japan, where the professional schools and the modern rule set took shape. Two rules — capture by surrounding, and no repetition — generate more complexity than any other board game.
Variant implemented
Japanese-style Go with area scoring, positional superko, 9×9 board by default (13×13 and 19×19 selectable), 6.5 komi, pass-pass ends the game.
Board and pieces
9×9 by default; 13×13 and 19×19 can be chosen when creating a room. Stones sit on the intersections.
Setup
An empty board. Black plays first.
Turn
Place a stone on an empty intersection, or pass.
Capture and scoring
A group with no liberties — no adjacent empty intersections — is removed from the board. Playing a stone that would leave your own group with no liberties is suicide and is illegal, unless the move captures.
Win condition
Two consecutive passes end the game. Score by area: your stones on the board plus the empty points surrounded only by your colour. White receives 6.5 komi, so a tie is impossible.
Draw condition
None. Komi is a half point.
Special rules
Repetition is governed by positional superko: a move may not recreate any earlier whole-board position. This subsumes the simple ko rule. A practical move limit of four times the board area ends a game that will not finish.
Computer opponent
A shallow search with a heuristic evaluation covering area, group liberties and captures, restricted to points near existing stones. This is a weak opponent. The AI interface is deliberately modular so a stronger engine can be connected without touching the rest of the platform.