Tanbo

Tanbo is a board game invented by Mark Steere in 1995. It typically uses a 19x19 Go board, but (like Go) it can be played on larger or smaller boards, depending on the intended length and depth of the game.

Some Tanbo-related terminology is as follows:

• A root is a collection of orthogonally connected stones of the same colour.
• A liberty is a location on the board into which a root could legitimtely be extended into; this is a close analogue to the same term in Go.

The rules of Tanbo are as follows:

• Set up a starting configuration of stones. A sample starting configuration on a 9x9 board is as follows; number signs represent black Go stones, zeroes represent white Go stones, and periods represent empty spaces:

 . . . . . . . . .
 . 0 . . . . . # .
 . . . . . . . . .
 . . . . . . . . .
 . . . . . . . . .
 . . . . . . . . .
 . . . . . . . . .
 . # . . . . . 0 .
 . . . . . . . . .

The starting configuration should be symmetric, and there should be an odd number of spaces between "adjacent[?]" stones to keep players from using a symmetric strategy. Like Go, Tanbo is played on the lines of the board instead of the squares themselves.

• Each player selects a colour of stone to use throughout the game. Black goes first.
• The current player must place one stone in such a way that it extends one of his roots; it must be orthogonally adjacent to one and only one stone of its own colour. Consider the following board section, Black to move, with at signs[?] representing legitimate moves and lowercase letters representing invalid moves:

 . @ a # @
 @ # # # @
 . b # c .
 . . @ . .
 . . d . .

(The periods represent invalid moves as well, but not shown as such for clarity.) a, b, and c represent moves which are invalid because they would be adjacent to more than one black stone; d is invalid because it is adjacent to none. All of the at signs are adjacent to one and only one black stone.

• If by placing such a stone causes any of the current player's roots to no longer have liberties, the roots are removed from the board. Another example with Black to move:

 a # # # #
 . . # . #
 # . # . #
 # # # . #
 # . # . #

Placement of a black stone at a would cause the black root to have no more liberties; the entire root will be removed if such a play is made.

• If and only if none of the player's roots have been removed, then the remaining liberties of the opponent's roots are considered. If any of the opponent's roots have no more liberties, they are removed from the board. For example, with Black to move:

 # # # # 0
 . . . # 0
 . . # # 0
 . . # 0 0
 . . a 0 .

Placement of a black stone at a will cause the white root to lose its last liberty; since the black root still has liberties after the black stone is placed at a, the white root is removed from the board.

• Play alternates until only one player has roots remaining; that player is the winner.

The official starting configuration of a 19x19 board is as follows, using the same symbolic representation as above:

 # . . . . . 0 . . . . . # . . . . . 0
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 0 . . . . . # . . . . . 0 . . . . . #
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 # . . . . . 0 . . . . . # . . . . . 0
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 . . . . . . . . . . . . . . . . . . . 
 0 . . . . . # . . . . . 0 . . . . . #

Need to add larger examples, half-played games, etc. etc. etc.

Tanbo can be played via eMail, using Richard Rognlie's Play-By-eMail Server.

Variations on the game inclue Hexbo[?] and Tanbo3D[?]; due to the structure of the ruleset, Tanbo is generalisable to any number of spatial dimensions.

References

Tanbo Rules, Mark Steere. http://www.gamerz.net/pbmserv/tanbo

External link

• Richard Rognlie's Play-By-eMail Server (http://www.gamerz.net/pbmserv/)