• Board and Pieces
• Classic Ordo
• Ordo X
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Ordo is played on a 10x8 board.

There are two players: Light and Dark.  Initially each player has 20 checkers of the corresponding color.

The initial position of the checkers is shown in the following picture:

The goal of Classic Ordo is to reach the opposite row with one of the player's checkers.  A player can also win the game by capturing all opponent's checkers or by breaking the group of opponent's checkers in such a way that the opponent is unable to reconnect his group on his next move.

Players move alternately, starting with the player controlling the light checkers.

During the game, after a player's move, all of that player's checkers must be connected (orthogonally or diagonally ) in one sole group.  If a group of a player's checkers is disconnected as a result of a capture made by the opponent, the player must move to reconnect his group again.  If no such move is possible, the player loses the game.

There are two kinds of moves: single checker moves and ordo moves.

A single checker can move straight forward, diagonally forward or sideways in a straight line any number of empty cells.  It may end the move in an empty cell or a cell occupied by an opponent's checker, which is then captured and removed from the board. The only case when a single checker can move backward or diagonally backward is when a group of a player's checkers is disconnected and he needs to reconnect it.  Below is an example of all possible moves that can be made by the highlighted checker:

The ordo move: a horizontal row of 2 or more checkers (an ordo) can move forward and a vertical row of 2 or more checkers (an ordo) can move sideways any number of empty cells. All ordo's checkers move in parallel directions the same number of cells and they may not capture opponent's checkers. The only case when an ordo can move backward is when a group of a player's checkers is disconnected and he needs to reconnect it.  Below are three examples of possible ordo moves (there are many other possible ordo moves in the illustration):

The goal of Ordo X is to reach the opposite row with one of the player's checkers or capture all opponent's checkers.

Players move alternately, starting with the player controlling the light checkers.

During the game, after a player's move, all of that player's checkers must be connected (orthogonally or diagonally ) in one sole group.

There are two kinds of moves: single checker moves and ordo moves.

A single checker (a singleton) can move straight forward, diagonally forward or sideways in a straight line any number of empty cells.  It may end the move in an empty cell or a cell occupied by an opponent's checker, which is then captured and removed from the board.

If by making a capturing move the player divides the group of the opponent's checkers into distinct sub-groups then he must also take away all opponent's checkers of any smaller sub-groups, such that only one (i.e. the largest) group remains. If there are two or more largest sub-groups with the same number of opponent's checkers, the player can decide which sub-group to leave on the board. Below are two examples of the capturing move:

This capturing move divides the opponent's group to three sub-groups: one checker, two checkers and 5 checkers. The two smaller groups are removed along with the captured checker.		This capturing move divides the opponent's group to two sub-groups of the equal size (5 checkers). The player may decide which sub-group to leave on the board.

The ordo move: a horizontal or vertical row of 2 or more checkers (an ordo) can move forward, diagonally forward or sideways any number of empty cells. All ordo's checkers move in parallel directions the same number of cells and they may not capture opponent's checkers. Below are some examples of possible ordo moves (there are many other possible ordo moves in the illustration):

This illustration shows three examples of the perpendicular ordo moves.		This illustration shows five examples of ordo moves in the same file		This illustration shows three examples of diagonal ordo moves

If the player moves a singleton or an ordo in a sideways direction then he must immediately make another move in a forward or diagonally forward direction before passing the the turn to his opponent. This second move can be made with the same or any other singleton or ordo. Both sideways and the following forward moves must be legal moves in every respect, e.g. they may not disconnect the player’s own group and must follow the common rules of singleton or ordo moves.

• Official Ordo site.
• Buy this game on nestorgames site.