Community variant

Trebuchet Chess

Bishops are replaced with the trebuchet which can move like a king as well as a bishop.

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: xxx
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), knight (n), pawn (p), piece (s) and custom piece 1 (t).
custom piece 1 (t) is a custom piece with Betza movement `BW`.

Promotion

The pieces that can promote are: pawn (p).
Promotion choices are both sides: knight (n), rook (r), custom piece 1 (t) and queen (q).

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.

Custom piece 1 (T) movement

BW

move capture move or capture initial only hopper target

Fairy-Stockfish rules

[trebuchetchess:chess]
# 1. Map 't' to customPiece1 with Bishop + 1-step Orthogonal (BW) movement
customPiece1 = t:BW

# 2. Perfect piece mapping: Standard array completely untouched, custom pieces appended at the end
pieceToCharTable = PNBRQKpnbrqkTt

# 3. Update the promotion rules to include 't' instead of 'b'
promotionPieceTypes = nrtq

# 4. Setup the starting board layout replacing 'b/B' with 't/T'
startFen = rntqktnr/pppppppp/8/8/8/8/PPPPPPPP/RNTQKTNR w KQkq - 0 1