The grasshopper is an unorthodox
chess piece invented in 1912 by
fairy chess pioneer and problem composer
Thomas Dawson. It is probably the most commonly used fairy piece. It can move in any direction that a
queen can, the difference being that the grasshopper must
jump over exactly one piece and land on the square immediately behind it. The piece jumped over may be of either colour.
If the landing square contains an enemy piece, it is of course
captured by the grasshopper. Consider the skeleton position where White has just a grasshopper on
a1, while Black has a king on h8 and pawn on g7. Then the black king is in check, and Black may escape
check not only by moving the king but also by moving the pawn (since then the grasshopper, having nothing to jump over along the a1-h8 diagonal, would no longer be attacking the king). The same idea shows that it is possible to give check from a grasshopper without moving it! One need only interpose another piece adjacent to the enemy king, providing a "springboard" for the grasshopper and therefore causing it to attack the king.
The grasshopper is denoted by a G and represented graphically by an upside-down queen.