Other Pieces

return to Variations on Go

Sculpture from Pei Hsiang Tang (China - 6th Century)Having collected an army and concentrated his forces,
he must blend and harmonize the different elements thereof
before pitching his camp.
[Sun Tzu, The Art of War - VII.2]

In traditional GO, there is just one piece. Let's call it the soldier. 

Unlike Chess, where there are a collection of different pieces having strange and dynamic movements, Go pieces are static and their force come from subtle influence and not from a strong and direct attack. 

Since the Go board is intended to represent a battle field and the soldier is a very weak piece taken alone, there should not be great differences between the pieces (for e.g., a chess Queen would be a very unbalanced piece inside a Go army). Also, the context of Go is an ancient or - at most - a medieval one, new pieces should try to reflect these concerns.


Here a short list of some pieces that does not move, but have different effects on the battle.


Any piece touching an ambassador (blue piece) cannot capture or be captured. Also, a drop near an ambassador cannot capture. In the left example, both players cannot play at [1], since that would mean a capture in the surroundings of an ambassador.


When a player drops a bomb (red piece) he decides between two states: a) immediate explosion: the bomb once it is dropped destroys all neighbors (and itself); and b) indirect explosion: the bomb only explodes when it is captured, destroying all neighbors (and itself). The destroyed pieces do not count as prisoners in both states.

Wall (or Pit)

A wall is an uncapturable neutral piece. This means that the maximum liberty of the neighbor cells are reduced by 1. In the example, cells [1] are in Atari. The white piece cannot escape from the black siege.


Any piece dropped within a distance of two cells of a Monk (green piece), cannot be used to capture other pieces. In the left example, Black cannot drop at [1] since [1] is within the Monk's influence area. However, White can drop at [2] to capture the black soldier.


A spy (violet piece), when dropped, changes the color of the adjacent soldiers (black turns white, white turns black). After that, its own color changes to the player's color, and then all eventual captures are done. The left example shows what happens (in clockwise fashion) when a spy is played at [1] by White.


The Tao is a 5x5 zone that enhances the soldier's mind and courage. All soldiers within the Tao's influence, can move one cell. In the example, the black stone can move all directions. However, if it moves north it will exit the Tao's influence and therefore cannot move anymore (except if a new Tao is dropped nearby).

Here a short list of some pieces that does move. All these piece have severe restrictions and should exist in short numbers, so the soldier remains the most important piece in a Go army.


The mercenary (brown piece) can move to an adjacent empty cell. Any player can move a mercenary (however, the Ko rule applies). In the example, if it moves south, it captures the black piece; if it moves north, it captures the white piece. A player can capture its own pieces using a mercenary. A mercenary can be captured.


A samurai can move like the mercenary but each one belongs to a specific player. Due to the tactical experience of the samurai, he can only move to a cell with at least three freedoms (so, it cannot move to a corner). Every friendly stone adjacent to the samurai, cannot be captured. However, the samurai himself may be captured.

In the example, the white samurai can move North (the white soldier gives him the required freedom) but not East.


The cavalry moves like the Chinese Xiang-Qi knight (i.e., does not jump) and has the samurai's freedom restriction and powers.

In the example, the black cavalry cannot move north, since the black soldier blocks his way. Also, it cannot move to cell [1], because the cell only has 2 freedoms.

So, let's give to each player an enhanced army to guide them to War.

War Go
  1. All Go rules apply, except:
  2. Each player have the following set of special pieces:
    1. One Ambassador
    2. Two Bombs
    3. Six Walls
    4. Four Spies
    5. Two Monks
    6. One Tao
    7. Two Mercenaries
    8. Four Samurais
    9. Two Cavalry units
  3. These pieces may be dropped anytime into the board (the target cells must be empty).

Other possible variants:

The center of Tao
  1. All Go rules apply, except:
  2. Initially, there are four Tao pieces in the center, making a 10x10 zone where soldiers can move.

Mercenary Go
  1. All Go rules apply, except:
  2. Initially, there are nine Mercenaries placed in the handicap cells.

Buying Armies
  1. All Go rules apply, except:
  2. Attribute a price for each piece.
  3. Give an initial credit for each player to build their specific armies.

Some go stones may be seen as holders of special powers (the next list is a reference of this site). And remember: the threat is more dangerous than the execution.


A stone that is equivalent to two eyes. This comes in two flavors: (i) only give life to friendly stones, or (ii) give life to any adjacent stone (of either color).


A stone that when dropped allows an extra move for the player. This is very powerful to eliminate living groups with single two eyes.


A piece that is able to replace an enemy stone.


When played, it can be later used to switch position with an enemy stone.

  Inner Strength

A stone that can be placed on a suicide position. Until played, living groups need 3 eyes.


A stone that connects any friendly stones separated by one cell (even if the in-between cell is occupied by an enemy stone). 


A stone which the opponent cannot drop adjacent to it.

  King's Son (by Stephen Loftus-Mercer)

Counts as -5 if it is captured but is otherwise a regular soldier on the field.

I define squadrons and platoons has groups of 3 and 4 connected pieces, respectively. In the following picture, it is displayed the possible 3 squadrons (with white pieces) and 7 platoons (with black pieces).

Other larger groups can be made. There are 15 different groups of 5 pieces (the pentominoes), 31 groups of 6 pieces (the hexaminoes), and so on...

Let's define a Go variant based on this concept:

Group Go
  1. All Go rules apply, except:
  2. Both players agree on having a specific set of squadrons and/or platoons.
  3. The groups may be dropped anytime into the board (the target cells must be empty).

There are two known variants based on this concept: (i) Omino Go (or Tetromino Go) by R. Wayne Schmittberger, explained in his book "New Rules for Classic Games", instead of playing one stone per turn, players drop a platoon. In Black’s first-turn, he can only play two stones, and (ii) Karl Knechtel's DominGo where both players drop 2x1 pieces (a domino) instead of single stones.

More information about polyominoes can be found at The Geometry Junkyard and in Alexandre Muņiz's Pentomination. Also, check the polyiamond, sexominoes and xominoes tilings.

Go is played with two colors (black and white). However, it's possible to imagine Go games where both players only have one type of stone (let's say gray or brown). Is it possible to imagine variants based on this premise? Some proposals:

[Martin Moller Pedersen] What about Tanbo but with two players use gray. The last player to put a stone legal on the board is the winner/loser?

[Pekka Karjalainen] [...] The players alternate placing one stone on any free space on the grid. For every square completed by the player he gains one point. First to gain M points wins the game. A square is any possible configuration of four stones that are placed so that they are at the corners of a square [diagonal squares included].

I present here another variant also based on squares:

Unsquare Go

Start with the Go board full of gray stones. Then, alternating moves, each player removes a stone (that stone is not captured). When a player makes a square, he captures all stones inside that square (no diagonal squares). When there are no capturable stones left on the board, wins the player with more captured stones.

If the next player removes g3, he creates a square with empty cells [1] and captures 7 stones. There is a move where it can be captured all but three stones. Where is it?

The rules of Go apply, except:

Some extra notes from the author: