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01Prepare an empty board

Two players need a grid board and contrasting stones. Use the intersections, including edges and corners—not the squares. Black starts; alternate placing one stone on an empty intersection or passing. Stones stay where placed unless captured. Aim to finish with more area, after White’s compensation points.

02Connect and capture

A liberty is an empty intersection immediately above, below, left or right. Same-color stones touching that way form a chain and share liberties; diagonal contact does not connect them. When your move removes an enemy chain’s last liberty, remove that chain. Then your own chain must have a liberty: self-capture is illegal, but a move that first captures enemies and creates liberties is legal.

Reference: British Go Association — play and liberties.

03A small capture example

Count liberties before each move. Two genuinely separate eyes can protect a connected group, but an apparent eye shared with disconnected stones can be false. Do not remove a group simply because it looks surrounded.

04Ko prevents an endless loop

Under AGA situational superko, a move cannot recreate an earlier board position with the same player next to move. This forbids immediate recapture in a simple ko. Play elsewhere first; after the opponent replies, a recapture is legal only if it does not violate the repetition rule.

05Pass, agree, then count

Give the opponent one of your stones when passing. Two consecutive passes pause play. Agree which stones are dead and remove them. If disputed, resume with the opponent of the last passer; play out the issue. If both immediately pass again without agreement, leave all stones for counting. White must make the final pass, adding a third pass if necessary. For area scoring, count your living stones plus empty regions bordered only by your color. Shared neutral points score for neither side. Ignore captured and pass stones in the area total; add 7.5 to White.

Reference: BGA — AGA scoring and ending summary.

06Score example and common mistakes

If Black has 31 living stones and 12 controlled empty intersections, Black scores 43. White with 29 stones and 9 controlled intersections scores 45.5 after komi; White wins by 2.5. These are illustrative totals. Do not add prisoners again, count diagonal contact as connection, or confuse area counting with territory-only counting. Finish neutral points before passing when they can safely add to your area.

Reference: BGA — introduction to AGA rules.