Rules & objective
Start with eight pieces each on 25 intersections. Move one piece to an adjacent empty point along a drawn line; no jumps or undrawn diagonals. Gánh converts enemies on opposite sides of the destination, possibly several pairs. Then Vây converts each connected enemy group with no adjacent empty point anywhere; an individual blocked piece in a group with a liberty is not converted. Pieces change ownership, never leave; total 16. Mở: after an opponent’s nonconverting move vacates a point where you can make a sandwich, your next move must enter that point and sandwich; choose any eligible source. No bonus move for conversion; alternate turns. Convert every opponent or leave no legal move to win. Bottom starts; new games alternate starters. Our declared digital draws are threefold identical board/turn/forced-response rights or 100 individual moves without conversion. Computer and hints use bounded search, not claimed perfect play.
Controls
Play directly on the cards or board with mouse or touch. Coordinate selectors are optional keyboard aids.
Worked example
After moving to an empty intersection, inspect opposing pieces on symmetric sides for a Gánh conversion. This is not ordinary one-piece capture.