Thinktank Chess is variant of International
Chess where all of the pieces other than the King and Queen move
differently when capturing from how they move when not capturing.
Such pieces are called are called divergent or sniper
pieces. Thinktank Chess was developed by Frank Maus in 1927, and is
also called Sniper Chess.
Board and Setup
In the graphics for the back-rank pieces other than the King
and Queen, the top of the pieces indicates how the piece
moves without capturing, and the bottom of the piece how it
captures. In the letter codes for those pieces, the first part
of the code indicates how the piece moves without capturing, and
the second part how it captures. Likewise with the names, the first
part of the name indicates how the piece moves without capturing,
and the second part how it captures. Thus, the Rookni, with a code
of R/N, moves like a Rook when not capturing, but moves to
capture like a Knight.
The game is conducted by rules of International
Chess with the following changes:
The setup is different (see the diagram above), with each side having
a King, a Queen, a Rookni, a Kniroo, a Bishkni, a Bisroo, a Knibis,
a Roobis and eight Pawns.
The King may castle with either the Rookni or the Roobis, under normal
castling rules.
Promotion is to any of the seven starting non-King, non-Pawn pieces.
The game is won by checkmating a player's King.
The Pieces and their Movements
The King, the
Queen, and the
Pawns move as
normal. The divergent back-rank pieces move as indicated in the
following table.
Piece
Starting Locations
Description
Rookni R/N
a1 a8
The Rookni moves like a Rook
when not capturing, but moves like a
Knight when capturing.
Kniroo N/R
b1 b8
The Kniroo moves like a Knight
when not capturing, but moves like a
Rook when capturing.
Biskni B/N
c1 c8
The Biskni moves like a Bishop
when not capturing, but moves like a
Knight when capturing.
Bisroo B/N
f1 f8
The Biskni moves like a Bishop
when not capturing, but moves like a
Rook when capturing.
Knibis N/B
g1 g8
The Kniroo moves like a Knight
when not capturing, but moves like a
Bishop when capturing.
Roobis R/B
h1 h8
The Rookni moves like a Rook
when not capturing, but moves like a
Bishop when capturing.
Maus intended these games to be played using a regular Chess set. He
suggested tying ribbons around the Kingside pieces to distinguish them
from the Queenside pieces.
Notes and Comments
There are other games with divergent pieces, for example all variants
that use FIDE Pawns or Xiangqi Cannons have divergent pieces. Some other
variants built around divirgent pieces are A.J. Winkelspecht's game
Divergent Chess,
Michael Howe's game Asymmetric
Chess, and Christian Freeling's game
Loonybird.
Given the names of these games -- Thinktank and Allthought -- one suspects
that Maus thought of these games as a sort of mental exercise. Indeed,
playing these variants with a regular Chess set might well give one some
of the same mental workout some people enjoy from
Ultima.
Zillions of Games
There is an implementation of Thinktank Chess and Allthought Chess
for Zillions of games. You can download it here:
