Community variant

Hopper

This is a user-catalogued casual variant. Technical details such as board size, FEN, pieces, and hand rules are defined in the Fairy-Stockfish variants.ini block below.

Uploaded by: King_Keeg
Visibility: public
Status: active

Generated rule overview

This variant inherits its base rules from `chess` and overrides the settings shown below.

Board and setup

Default starting position

Pieces and movement

The piece set used on the board is: king (k), queen (q), rook (r), bishop (b), knight (n), pawn (p) and Grasshopper (s).
Grasshopper (s) is a custom piece with Betza movement `fmWfcF G`.

Promotion

The pieces that can promote are: pawn (p).
Promotion choices are both sides: queen (q), rook (r), bishop (b) and knight (n).

Piece movement

These diagrams show custom pieces and known Fairy-Stockfish built-in fairy pieces from White's perspective on a compact preview board. Some special moves, especially hoppers and game-state-dependent moves, can still depend on blockers or game state.

Grasshopper (S) movement

fmWfcF G

move capture move or capture initial only hopper target

Fairy-Stockfish rules

[pawngrasshopper:chess]
# 1. Define the Pawn-Grasshopper ('s'):
# - fmW : Step forward 1 square (non-capturing)
# - fcF : Capture diagonally forward 1 square
# - G   : Grasshopper move (hop over any intervening piece along queen lines to land immediately behind it)
customPiece1 = s:fmWfcF G

# 2. Designate 's' as a pawn type so it promotes on the back rank
pawnTypes = s

# 3. Standard promotion pieces allowed (Queen, Rook, Bishop, Knight)
promotionPieceTypes = qrbn

# 4. Asymmetric starting position: White uses Pawn-Hoppers ('S'), Black uses standard pawns ('p')
startFen = rnbqkbnr/pppppppp/8/8/8/8/SSSSSSSS/RNBQKBNR w KQkq - 0 1