Pachisi is a board game thought to originate in India; it is described as the national game of India. It is played on a board shaped like a symmetrical cross. A player's pieces move around the board based upon a throw of six or seven cowries (the number of shells landing aperture upwards indicating the number of places to move).

The name of the game comes from the Hindu word pachis, meaning twenty-five, the largest score that can be thrown with the cowrie shells. Thus the game is also known by the name Twenty-five.

Each player's objective is to move all four of their pieces completely around the board, anticlockwise, before their opponents do. The pieces start and finish on the Charkoni.

The playing order is decided by each player throwing the cowries. The player with the highest score starts, and turns continue anticlockwise around the board.

Each player's first piece may leave the Charkoni on any throw. Each player moves their pieces down the centre column of their own arm of the board, then anticlockwise around the outside columns.

A player may have any number of their pieces on the board at one time. One piece only may be moved with a single throw, or if the player chooses, they can decline to move any piece on a throw.

If a 6, 10 or 25 is thrown, the player gets a grace. This enables them to introduce another of their pieces from the Charkoni onto the board, and they also get to repeat their turn.

More than one piece of the same team may occupy a single square. However a piece may not move onto a castle square that is already occupied by an opponent's piece.

If a piece lands on a square (other than a castle square) occupied by any number of the opponent's pieces, those pieces are captured and must return to the Charkoni. Captured pieces may only enter the game again with a grace throw. A player making a capture is allowed another turn.

A piece completes its trip around the board by moving back up its central column. Returning pieces may be placed on their side in order to distinguish them from pieces that have just entered. A piece can only return to the Charkoni by a direct throw.

Four of the castle squares are placed so that they are exactly 25 moves from the Charkoni. A common strategy is for returning pieces to stay on these squares, where they are safe from capture, until a 25 is thrown. Then they can finish the game directly. This is where the name of the game comes form