Co Ganh — a beginner's guide (English)

Co Ganh is a folk game of Vietnam played on a 5×5 board with diagonals at certain intersections (Alquerque-style). Each side has 8 discs — red on the top two rows, blue on the bottom two rows, the middle row empty. There are no ranks: every piece moves and captures the same way, and strength is purely positional. Blue moves first.

Movement: on your turn, move one of your pieces along a drawn line to an adjacent empty intersection. No jumping.

Captures — the pieces flip instead of leaving the board:

• Gánh: when your piece moves into the exact middle of two enemy pieces on a straight line (Enemy–You–Enemy, three consecutive points), both enemies flip to your color. One landing can gánh on multiple axes at once (double, even triple gánh).
• Chẹt: after each move, any enemy group (same-color pieces connected along the lines) left with no empty neighboring point is flipped to your color in full — you "surround" them by taking their last breathing space.

Safe self-surround: moving your own pieces into a fully enclosed position never flips them; only your opponent can capture you. Luật Mở: if you have any gánh move, you must play one (any one of them).

Win by flipping all enemy pieces or leaving the opponent with no legal move; draws only by mutual agreement.

Tip: the center intersection (where orthogonal and diagonal lines all cross) is the strongest point on the board — hold it and multi-axis gánh opportunities open up.

Play free at coganh.synerworlds.com — vs-computer with a 12-level ladder, daily puzzles, and rooms to challenge friends. No install needed.

Related guides

• Co Nhao — a beginner's guide — leap-capture folk game on a 5×5 board, Co Ganh's close cousin.
• O An Quan — a beginner's guide — the beloved stone-sowing game of Vietnamese childhood.
• Ca Ngua — a beginner's guide — the family horse-racing board game.

Read next: beyond the rules

• Cờ Gánh endgames: winning by blockade, liberty races, and the two faces of the fortress
• Common Cờ Nhào mistakes: parity blindness, self-blocking, and forgetting the reply chain