The pincer pawn was invented by Robert Abbott for his game Ultima
. The rules for Ultima were first published in 1962.
Movement
The pincer pawn moves as a chess rook, but does
not capture this way, and can never move to an occupied square. When a
pincer pawn ends its move on a square orthogonally adjacent to an enemy
piece, and on the square immediately opposite that piece from the piece
is a piece the same color as the pawn, then the enemy piece is captured.
A pincer pawn can capture up to three pieces in one move.
Movement diagram
In the diagram below, the pincer pawn on d5 (represented by the symbol
for the pawn, since the game Ultima uses a chess pawn to represent the
pincer pawn) can move to any of the squares marked with a black circle.
If the pincer pawn moves to d3, it captures the black rook (since it is
sandwiched between the pawn and the white bishop). If the pincer pawn
moves to f5, it captures all three black pawns. Note that moving the
white knight to b5 does not result in a capture of the black knight on
c5 - a capture only occurs when the pawn moves.
Remarks
Pincer pawns are generally more powerful than their chess counterparts;
they are not confined to a fraction of the board, and can often capture
defended pieces without fear of retribution. The pincer pawn's weakness
is that it can not capture without the aid of another piece. The pincer
pawn can never capture a piece in the corner of the board.
