- 10 × 8 game board
- 2 × 20 pieces in two colors
Orthogonally or diagonally connected group of all pieces of a player.
A single piece (in contrast to an → ordo).
Orthogonally (in a straight horizontal or vertical line) connected group of two or more pieces of a player.
Nearest row on the board seen from a player’s perspective.
Pieces are setup as shown in figure 3.
Players move their pieces trying to reach the opponent’s home row.
Players choose their colors and take a seat on their side of the board. White starts, then players take turns making a move. They may not pass.
Moves and Captures
In general, pieces move (orthogonally or diagonally) forward or sideways, never backwards.
A sideways move must be instantly followed by any other move (including the same or other pieces, but now forward only) in the same turn. Apart from that, a sideways move is a regular move in every respect (see below).
There are two possible ways to move the pieces: singleton moves and ordo moves.
A singleton can move forward or sideways, orthogonally or diagonally in a straight line any number of empty squares. It may end the move in an empty square or a square occupied by an opponent’s piece, which is then captured and removed from the board.
A group of more than one piece, which is connected in a straight horizontal or vertical (never diagonal!) line (a so called “ordo”), can move side by side or go in single file any number of empty squares. It may move orthogonally forward, diagonally forward, or sideways. It must move in parallel and it may not capture.
If a player disconnects the opponent’s group by capturing a piece, then said player must also remove all opponent pieces, which are not part of the largest subgroup. If there are subgroups with the same number of pieces, the attacking player may choose the pieces to remove.
End of the Game
The main goal of the game is to place (at least) one piece on the opponent’s home row.
Also, a player wins the game if he manages to capture all pieces of the opponent.
If a player has only one piece left, said piece is still considered a group!
These are extended rules for original Ordo. They provide more tactical possibilities and gameplay is faster.
Ordo X uses the same material as original Ordo.
This version: October 6th, 2009