1. To start the game you need a game board no smaller than 8x8. An board 8x12 is recommended, but 12x12 can also be used.

2. Players need to pick their color for the game pieces. Usually black and white.

3. Black starts the game.

1. The gameboard of Ludus Calculorum

2. A double open-ended row of three is forbidden unless a player is forced to make that play. This refers to a row of three that simultaneously goes in two directions, forming a cross, an X shape or a T shape.

3. This rule is exists because once constructed, such an alignment makes for a very easy win.

4. Each player can place one game piece in one turn.

1. The first player to make a vertical, horizontal, or diagonal line of five game pieces is the winner.

2. If the board becomes filled and no more moves can be made, the game is a draw.

Players try to place a vertical, horizontal, or diagonal line of five game pieces.

1. Calculi is a game that comes from Ancient Rome. It is a very simple yet fun and challenging game.

2. Calculi is sometimes referred to as the Roman checkers