How to play
Pieces. Nine three-sided blocks share one tray of nine slots. Each block shows one face at a time: a square, a pentagon or a circle. The blocks belong to no one.
Your turn. Do exactly one of three things: place a new block, square face up, in any empty slot; slide any block on the tray to another empty slot; or flip a block one step forward, square to pentagon, or pentagon to circle. A circle can never be flipped back.
Scoring. Whenever your action completes a row, column or diagonal of three matching faces that was not complete before, you score one point for each such line.
End. The game ends when all nine slots hold circles. The highest score wins.
Descriptions of the game say only "three in a row"; this version reads that as three of the same shape, which keeps the flips meaningful.