Achi is a two-player abstract strategy game from Ghana. It is related to tic-tac-toe, but even more related to Tapatan, Three Men's Morris, Nine Holes, Tant Fant, Shisima, and Dara, because pieces are moved on the board to create the 3 in-a-row. It is an alignment game.
There are two versions to this game. In one version, each player has four pieces to drop. This is the version described below. In another version, each player has only three pieces to drop, which makes it identical to Tapatan.
To create a 3 in-a-row of one's pieces either horizontally, vertically, or diagonally.
A 3 x 3 board is used. Three horizontal lines form the three rows. Three vertical lines form the three columns. Two diagonal lines connect the two opposite corners of the board. Each player has four pieces. One plays the black pieces, and the other plays the white pieces, however, any two colors or distinguishable objects will suffice.
The board is easily drawn on the ground or paper.
Rules and Game Play
1. The board is empty in the beginning.
2. Players decide what colors to play, and who will start first.
3. Drop phase: Each player drops one piece per turn on any vacant space on the board. Players alternate their turns. Pieces cannot move until all four pieces have been dropped.
4. Move phase: After each player's four pieces have been dropped on the board, each piece can move one space at a time following the pattern on the board. Only one piece can be moved per turn.
5. Players can create the 3 in-a-row at either the drop phase or move phase, and win the game.
6. HOUSE RULES: These are rules that you and the other player can agree upon. They are not standard for the game.
a) A stalemate where one player cannot make a move is cause for a draw or a loss to that player.
b) Repeating a position three times can be cause for a draw.
Analysis has shown that the first player wins with perfect play.
In the 3 piece variant where each player drops each of their 3 pieces on the board, there are 1,680 ways for that to happen. It is truly a complex game.
Cited as a predecessor of Three Men's Morris