Ordo
Ordo Rulebook
Table of Contents
Table of Contents
Material
Ordo is played on a 10 × 8 board with 2 × 20 pieces in two colors.
Terminology
- Home row: Nearest row on the board seen from a player's perspective.
- Group: Orthogonally or diagonally connected group of all pieces of a player. Pieces of the same color are connected forming a group.
Setup
Pieces are setup as shown in the figure (use the small dots on the board as guides).
Objective
Players try to reach the opponent's home row with at least one of their pieces.
Play
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.
Connection
Throughout the game, after a player's move, all pieces of that player must be connected in one sole group.
The number of pieces a player has in play may be reduced to a single piece, which is then still considered a group. Please note, that this minimal "group" is always in a connected state!
When pieces are moved in Ordo, there is a distinction between singleton moves and so called "ordo moves".
Singleton moves
A single piece can move forward or sideways, orthogonally or diagonally in a straight line any number of empty squares. It may end the move on an empty square or a square occupied by an opponent's piece, which is then captured and removed from the board.
Example: The marked piece has five possible moves. Please note, that moving one space ahead is not allowed as it would split the group.
Ordo moves
Two or more pieces, which are connected in a straight horizontal or vertical (not diagonal) line, can move side by side any number of empty squares. They may only move orthogonally (not diagonally) forward (if they are horizontally aligned) or sideways (if they are vertically aligned). They move together the same number of squares. They may not capture.
Disconnection
If a player's group is disconnected because of a capture move by the opponent, then that player must make a move, which reconnects his group again. If no such move is possible, the player loses the game immediately.
Pieces may normally move only forward or sideways. In case of a split group (and only then), they may also move backward. It can be a singleton or ordo move.
End of the Game
There are three situations in which the game ends:
- A player wins if he places at least one piece on the opponent's home row.
- A player wins if he can capture the very last piece of the opponent.
- A player loses if his group was split by a capture move of the opponent and he is not able to reconnect it again at the end of his turn.
Ordo X
If you are familiar with Standard Ordo you may also try out the extended or "X" rules, which are explained in the following.
Ordo X offers more move options, it is much faster and promotes offensive play.
All definitions and rules for the setup, the objective, and singleton moves stated up this point are the same.
The X rules differ in the following parts:
- Capture and disconnection
- Ordo moves
- Sideways moves
Capture and Disconnection
If a player disconnects the group of the opponent by a capture move, he must also remove all pieces of any smaller isolated sub-group, such that only one (i. e. the largest) group remains. If there are sub-groups with the same number of pieces, the attacker may decide which sub-group(s) to remove.
As usual, isolated single pieces also form a "group".
Example: White captures an opponent piece and removes 2 additional pieces of the smaller black, now isolated sub-group.
Please note, that the automatic capture of sub-groups makes the reconnection rules of standard Ordo obsolete, as disconnected groups do not longer occur. Also players cannot lose a game by disconnection in Ordo X.
Ordo Moves
Ordo moves are possible in diagonal directions as well.
Ordos may move diagonally as well. Please note that the two pieces on the left (in the diagram) are not ordo-aligned and therefore may not be moved in parallel.
Ordo moves in single file are allowed. Again, ordos are only horizontally or vertically aligned, thus a diagonal-aligned move is not allowed.
Pieces in an ordo alignment now move exactly like singletons, only in parallel. Please note: Ordo alignments (as opposed to ordo movements) are still only horizontal or vertical (never diagonal). Furthermore, capturing is still not possible with an ordo maneuver.
Sideways Moves
Singleton and ordo moves in a sideways direction (to the left or to the right) are now considered "preparation moves", i. e. they must be immediately followed by a forward (singleton or ordo) move. This second move (made in the same turn) can include the same or any other piece(s).
It is not allowed to make a sideways move
- on its own, or
- followed by another sideways move.
Apart from that, sideways moves must be legal moves in every respect:
- they may not disconnect the player's own group, and
- they can be singleton capture moves possibly followed by a removal of opponent sub-groups (see above).
Example: White makes a sideways move to the right (1) creating a 2-piece ordo which then (in the same turn) can move diagonally (2) towards the opponent home row and win the game.
End of the Game
In Ordo X, like in Standard Ordo, a player wins if he places at least one piece on the opponent's home row or captures the very last piece of the opponent.
Tactics
The number of pieces is not relevant for a win. Actually, as it is not easy to bring a larger number of pieces forward when they have to stay connected all the time, players may gain a more advantageous position if they have fewer pieces. Please note that a single piece can be moved very freely as it is still considered a group and therefore "always connected".
On the other hand you have to stop your opponent to march through your lines so you will need a certain number of pieces to wall him off.
This is the dilemma that makes Ordo so interesting.